user-1: I've tried hard to practice meditation - Anapansatti & Vipassana but I just can't concentrate on my breath. Now, I'm feeling inferior as if I can never concentrate my breath or get rid of my inner problems/ sufferings. I feel as if peace or enlightenment or eradication of suffering is not for me. 
After proper analysis, I've found that I just simply can't concentrate. So my questions are

What are necessary & sufficient condition to get enlightened? If I don't have those qualities how can I develop those qualities? What I would have to do?
How to concentrate provided I have tried my best to concentrate my breathing but mind wanders away in no time. It is making me sick thinking I don't posses qualities to eradicate my own sufferings. It makes me feel as if I will never be at peace. 

Note: I have been into 10 days Vipassana course also. 
Anyone help me. 

user12922: I believe it is important to not judge your practice. Simply continue, and use these feelings you are experiencing as something to observe. What you are dealing with is much more common than you may realize, and has nothing to do with whether you are "good" or "bad" at meditation. Don't fight these thoughts of inferiority, but practice seeing if you can let them come and go without overwhelming you.
When it storms outside, feel free to watch, but do not open the window. 

user-1: I was talking to my friend a few years back.  She is a yoga instructor and we got on the subject of meditation.  She asked how many hours a day I meditated and was taken a little aback by my answer.  "How can you sit so long!  I much rather be working in the garden or hiking.  That's my meditation and I can do that all day!"
In a rare instance of wisdom, I refrained from explaining to her that what she was doing wasn't really meditation.  It's a good thing I did, because looking back, I now realize that I would have been completely and utterly wrong.  Meditation doesn't have to be sitting meditation.  Not at first anyway.  Buddhist samatha and vipassana practice are simultaneously a mental and a somatic exercise.  For some people, this is not an issue.  Mind and body soften and settle together.  But some people need a little something extra.  You seem to be in that camp.  Instead of rushing right into sitting, why not try a bodily practice first?  Do something like hiking or walking, tai chi, or yoga.  You could even do an immersive activity like gardening or woodworking.  Practices like this go a long way to calm the mind.  They do it almost completely by accident in a way that is on the same spectrum as seated meditation.  The practice itself doesn't matter.  How good you are at it doesn't matter.  All that matters is that you let allow the physical discipline to tame your mind.  It will all on its own. 
Most importantly, however - and if you take away nothing else, let it be this -my friend can garden all day because she loves it.  I can meditate as much as I do because I feel the same.  It doesn't sound like you love your meditation practice.  And why should you?  It's clearly causing you frustration.  But it doesn't have to.  Think back to when you were a kid and were playing with your toys.  Did you really care if you were good at playing?  Were you sad if one play session didn't go as well as another?  Was playing some sort of transactional system that you thought would have yields proportional to the time you invested in it?  Of course not.  You played because you loved it.  I'd even go so far as to say that you played just to play.  Meditation is no different.  Approach it with the same spirit.                

user43: Whenever anyone has a problem like this, I'm always reminded of Dutiya Anuruddha Sutta (AN 3.128/130/131 in different versions):

Then venerable Anuruddha came to venerable Shariputra and said:  
-- As much as I, friend Shariputra, look at things with purified Heavenly Eye, see things with thousandfold-superhuman vision, train in confidence unmovable, in awareness undimmable, in tranquillity imperturbable, and in focused mind unscattered, still I can't "having stopped maintaining intoxication, achieve liberation of mind".  
-- All these thoughts, friend Anuruddha, of the kind "I look at things with purified Heavenly Eye, I see things with thousandfold-superhuman vision" -- this is your conceit.  
And the thoughts of the kind "I train in confidence unmovable, in awareness undimmable, in tranquility imperturbable, and in focused mind unscattered" -- this is your pathological restlessness.  
And the thoughts of the kind "still I can't "having stopped maintaining intoxication, achieve liberation of mind" -- this is your remorse.  
You'd better, friend Anuruddha, these three thoughts abandon; To these three thoughts not attending, to The Unconditional point your mind.

The point being, these instances of worry and inferiority are the exact problems we are supposed to solve in Buddhism. The Buddhist path is not to heap on more goals and expectations and worries - but to in fact let go of them, to have less of them - in order to attain peace of mind. The element of Sila or morals in Buddhism exists to help one be free of regrets, not to have more reasons for regret! The element of "concentration" (I'd rather say "attention control") is practiced to make one free from worry, not to worry even more about one's inability to control attention. So just remember that everything in Buddhism is done with peace as its goal, dispassion as its goal, liberation as its goal - not to torture oneself. This way all your practice and meditation becomes an act of healing and rest, not an act of fighting.

user-1: as i see it in OP based solely on content of his post.

The faculty of conviction - seems to appear 
  The faculty of persistence - seems to appear 
  The faculty of mindfulness - seems to appear
  The faculty of concentration - self reported weak
  The faculty of discernment - seems to appear

Indriya-vibhanga Sutta: Analysis of the Mental Faculties 
On concentration:

"And what is the faculty of concentration?  There is the case where a
  monk, a disciple of the noble ones, making it his object to let go,
  attains concentration, attains singleness of mind. 

So it has attainment of singleness of mind as property of mind.
So how to develope it:
https://suttacentral.net/en/ma42

At that time, the Venerable Ānanda rose from his seat of repose in the
  afternoon and went to Buddha. He bowed his head at his feet and then
  withdrew to sit at one side. He said: “World Honored One, what is the
  meaning of this: ‘to keep precepts’?”
The World Honored One replied: “Ānanda, the meaning of keeping the
  precepts is to bring about non-regret. Ānanda, if someone were to keep
  the precepts, he would readily attain non-regret.”

https://suttacentral.net/en/an10.2

(1)–(2) “Bhikkhus, for a virtuous person, one whose behavior is
  virtuous, no volition need be exerted: ‘Let non-regret arise in me.’
  It is natural that non-regret arises in a virtuous person, one whose
  behavior is virtuous.
(3) “For one without regret no volition need be exerted: ‘Let joy
  arise in me.’ It is natural that joy arises in one without regret.
(4) “For one who is joyful no volition need be exerted: ‘Let rapture
  arise in me.’ It is natural that rapture arises in one who is joyful.
(5) “For one with a rapturous mind no volition need be exerted: ‘Let
  my body be tranquil.’ It is natural that the body of one with a
  rapturous mind is tranquil.
(6) “For one tranquil in body no volition need be exerted: ‘Let me
  feel pleasure.’ It is natural that one tranquil in body feels
  pleasure.
(7) “For one feeling pleasure no volition need be exerted: ‘Let my
  mind be concentrated.’ It is natural that the mind of one feeling
  pleasure is concentrated.

Later again from Meanings Sutta but it fit here more in this post:

Again, he asked: “World Honored One, what is the meaning of this:
  ‘concentration’?”
The World Honored One replied: “Ānanda, the meaning of concentration
  is to bring about seeing according to reality and knowing according to
  reality. Ānanda, if someone were to be concentrated, he would readily
  attain the seeing that is according to reality and the knowing that is
  according to reality.”

Else?
For developing  of non-distractiveness association with people collected in mind, avoiding restless people and mindfulness of arising and ceasing of phenomena in general according to Buddhagosa s commentary
I think this is it for your concentration problem OP, dont think i have to state the seemingly obvious in regards to your leaks:)
In regards to feeling inferior, 

there is no competition in search for peace

i heard that
Also this
Sarakaani Sutta:

"Take the case of another man. He is not even endowed with unwavering
  devotion to the Buddha, the Dhamma, the Sangha. He is not joyous and
  swift in wisdom and has not gained release. But perhaps he has these
  things: the faculty of faith, of energy, of mindfulness, of
  concentration, of wisdom. And the things proclaimed by the Tathaagata
  are moderately approved by him with insight. That man does not go to
  the realm of hungry ghosts, to the downfall, to the evil way, to
  states of woe.
"Take the case of another man. He is not even endowed with unwavering
  devotion to the Buddha, the Dhamma, the Sangha. He is not joyous and
  swift in wisdom and has not gained release. But he has just these
  things: the faculty of faith, of energy, of mindfulness, of
  concentration, of wisdom. Yet if he has merely faith, merely affection
  for the Tathaagata, that man, too, does not go to... states of woe.

On Vi:
When training Satipatthana it is not the objective to get well-concentrated, the concentration comes in succession and has its role and appropriate function. IE it also is involved as a causal condition for people attaching to certain states and that hinders progress.
Sati as a factor of Enlightenment, translated as mindfuless has function of remembering or keeping in mind, re-cognizing. Mindfulness of physical and mental states arising of and within a body is a single theme for the mind, which will develope concentration faculty no problem.
It seems to me that you could try paying more attention to arising and passing of states of "disliking", "wanting/liking", "sadness/despair", "judging/evaluating", "doubting" and "thinking/wondering" as well as "knowing", knowing ie when your concentration is low you can know it as "my concentration is weak", then maybe "disliking?;)" or "wanting" for it to be better or "evaluating" that it makes you a bad meditator, should note that your are thinking at this point and see where it goes from there. You see it will keep you within the theme of mindfulness of the body, conditioning victory.

-1: <p>I've tried hard to practice meditation - Anapansatti &amp; Vipassana but I just can't concentrate on my breath. Now, I'm feeling inferior as if I can never concentrate my breath or get rid of my inner problems/ sufferings. I feel as if peace or enlightenment or eradication of suffering is not for me. </p>

<p>After proper analysis, I've found that I just simply can't concentrate. So my questions are</p>

<ul>
<li><p>What are necessary &amp; sufficient condition to get enlightened? If I don't have those qualities how can I develop those qualities? What I would have to do?</p></li>
<li><p>How to concentrate provided I have tried my best to concentrate my breathing but mind wanders away in no time. It is making me sick thinking I don't posses qualities to eradicate my own sufferings. It makes me feel as if I will never be at peace. </p></li>
</ul>

<p>Note: I have been into 10 days Vipassana course also. </p>

<p>Anyone help me. </p>
 12922: <p>I believe it is important to not judge your practice. Simply continue, and use these feelings you are experiencing as something to observe. What you are dealing with is much more common than you may realize, and has nothing to do with whether you are "good" or "bad" at meditation. Don't fight these thoughts of inferiority, but practice seeing if you can let them come and go without overwhelming you.</p>

<p><em>When it storms outside, feel free to watch, but do not open the window.</em> </p>
 -1: <p>I was talking to my friend a few years back.  She is a yoga instructor and we got on the subject of meditation.  She asked how many hours a day I meditated and was taken a little aback by my answer.  "How can you sit so long!  I much rather be working in the garden or hiking.  That's my meditation and I can do that all day!"</p>

<p>In a rare instance of wisdom, I refrained from explaining to her that what she was doing wasn't really meditation.  It's a good thing I did, because looking back, I now realize that I would have been completely and utterly wrong.  Meditation doesn't have to be sitting meditation.  Not at first anyway.  Buddhist samatha and vipassana practice are simultaneously a mental and a somatic exercise.  For some people, this is not an issue.  Mind and body soften and settle together.  But some people need a little something extra.  You seem to be in that camp.  Instead of rushing right into sitting, why not try a bodily practice first?  Do something like hiking or walking, tai chi, or yoga.  You could even do an immersive activity like gardening or woodworking.  Practices like this go a long way to calm the mind.  They do it almost completely by accident in a way that is on the same spectrum as seated meditation.  The practice itself doesn't matter.  How good you are at it doesn't matter.  All that matters is that you let allow the physical discipline to tame your mind.  It will all on its own. </p>

<p>Most importantly, however - and if you take away nothing else, let it be this -my friend can garden all day because she loves it.  I can meditate as much as I do because I feel the same.  It doesn't sound like you love your meditation practice.  And why should you?  It's clearly causing you frustration.  But it doesn't have to.  Think back to when you were a kid and were playing with your toys.  Did you really care if you were good at playing?  Were you sad if one play session didn't go as well as another?  Was playing some sort of transactional system that you thought would have yields proportional to the time you invested in it?  Of course not.  You played because you loved it.  I'd even go so far as to say that you played just to play.  Meditation is no different.  Approach it with the same spirit.                </p>
 43: <p>Whenever anyone has a problem like this, I'm always reminded of Dutiya Anuruddha Sutta (AN 3.128/130/131 in different versions):</p>

<blockquote>
  <p>Then venerable Anuruddha came to venerable Shariputra and said:  </p>
  
  <p>-- As much as I, friend Shariputra, look at things with purified Heavenly Eye, see things with thousandfold-superhuman vision, train in confidence unmovable, in awareness undimmable, in tranquillity imperturbable, and in focused mind unscattered, still I can't "having stopped maintaining intoxication, achieve liberation of mind".  </p>
  
  <p>-- All these thoughts, friend Anuruddha, of the kind "I look at things with purified Heavenly Eye, I see things with thousandfold-superhuman vision" -- this is your conceit.  </p>
  
  <p>And the thoughts of the kind "I train in confidence unmovable, in awareness undimmable, in tranquility imperturbable, and in focused mind unscattered" -- this is your pathological restlessness.  </p>
  
  <p>And the thoughts of the kind "still I can't "having stopped maintaining intoxication, achieve liberation of mind" -- this is your remorse.  </p>
  
  <p>You'd better, friend Anuruddha, these three thoughts abandon; To these three thoughts not attending, to The Unconditional point your mind.</p>
</blockquote>

<p>The point being, these instances of worry and inferiority are the exact problems we are supposed to solve in Buddhism. The Buddhist path is <em>not</em> to heap on more goals and expectations and worries - but to in fact let go of them, to have less of them - in order to attain peace of mind. The element of Sila or morals in Buddhism exists to help one be free of regrets, not to have more reasons for regret! The element of "concentration" (I'd rather say "attention control") is practiced to make one free from worry, not to worry even more about one's inability to control attention. So just remember that everything in Buddhism is done with peace as its goal, dispassion as its goal, liberation as its goal - not to torture oneself. This way all your practice and meditation becomes an act of healing and rest, not an act of fighting.</p>
 -1: <p>as i see it in OP based solely on content of his post.</p>

<blockquote>
  <p>The faculty of conviction - seems to appear 
  The faculty of persistence - seems to appear 
  The faculty of mindfulness - seems to appear
  The faculty of concentration - self reported weak
  The faculty of discernment - seems to appear</p>
</blockquote>

<p>Indriya-vibhanga Sutta: Analysis of the Mental Faculties </p>

<p>On concentration:</p>

<blockquote>
  <p>"And what is the faculty of concentration?  There is the case where a
  monk, a disciple of the noble ones, making it his object to let go,
  attains concentration, attains <strong><em>singleness of mind</em></strong>. </p>
</blockquote>

<p>So it has attainment of singleness of mind as property of mind.</p>

<p>So how to develope it:
<a href="https://suttacentral.net/en/ma42" rel="noreferrer">https://suttacentral.net/en/ma42</a></p>

<blockquote>
  <p>At that time, the Venerable Ānanda rose from his seat of repose in the
  afternoon and went to Buddha. He bowed his head at his feet and then
  withdrew to sit at one side. He said: “World Honored One, what is the
  meaning of this: ‘to keep precepts’?”</p>
  
  <p>The World Honored One replied: “Ānanda, the meaning of keeping the
  precepts is to bring about non-regret. Ānanda, if someone were to keep
  the precepts, he would readily attain non-regret.”</p>
</blockquote>

<p><a href="https://suttacentral.net/en/an10.2" rel="noreferrer">https://suttacentral.net/en/an10.2</a></p>

<blockquote>
  <p>(1)–(2) “Bhikkhus, for a virtuous person, one whose behavior is
  virtuous, no volition need be exerted: ‘Let non-regret arise in me.’
  It is natural that non-regret arises in a virtuous person, one whose
  behavior is virtuous.</p>
  
  <p>(3) “For one without regret no volition need be exerted: ‘Let joy
  arise in me.’ It is natural that joy arises in one without regret.</p>
  
  <p>(4) “For one who is joyful no volition need be exerted: ‘Let rapture
  arise in me.’ It is natural that rapture arises in one who is joyful.</p>
  
  <p>(5) “For one with a rapturous mind no volition need be exerted: ‘Let
  my body be tranquil.’ It is natural that the body of one with a
  rapturous mind is tranquil.</p>
  
  <p>(6) “For one tranquil in body no volition need be exerted: ‘Let me
  feel pleasure.’ It is natural that one tranquil in body feels
  pleasure.</p>
  
  <p>(7) “For one feeling pleasure no volition need be exerted: ‘Let my
  mind be concentrated.’ <strong>It is natural that the mind of one feeling
  pleasure is concentrated.</strong></p>
</blockquote>

<p>Later again from Meanings Sutta but it fit here more in this post:</p>

<blockquote>
  <p>Again, he asked: “World Honored One, what is the meaning of this:
  ‘concentration’?”</p>
  
  <p>The World Honored One replied: “Ānanda, the meaning of concentration
  is to bring about seeing according to reality and knowing according to
  reality. Ānanda, if someone were to be concentrated, he would readily
  attain the seeing that is according to reality and the knowing that is
  according to reality.”</p>
</blockquote>

<p>Else?</p>

<p>For developing  of non-distractiveness association with people collected in mind, avoiding restless people and mindfulness of arising and ceasing of phenomena in general according to Buddhagosa s commentary</p>

<p>I think this is it for your concentration problem OP, dont think i have to state the seemingly obvious in regards to your leaks:)</p>

<p>In regards to feeling inferior, </p>

<blockquote>
  <p>there is no competition in search for peace</p>
</blockquote>

<p>i heard that</p>

<p>Also this</p>

<p>Sarakaani Sutta:</p>

<blockquote>
  <p>"Take the case of another man. He is not even endowed with unwavering
  devotion to the Buddha, the Dhamma, the Sangha. He is not joyous and
  swift in wisdom and has not gained release. But perhaps he has these
  things: the faculty of faith, of energy, of mindfulness, of
  concentration, of wisdom. And the things proclaimed by the Tathaagata
  are moderately approved by him with insight. That man does not go to
  the realm of hungry ghosts, to the downfall, to the evil way, to
  states of woe.</p>
  
  <p>"Take the case of another man. He is not even endowed with unwavering
  devotion to the Buddha, the Dhamma, the Sangha. He is not joyous and
  swift in wisdom and has not gained release. But he has just these
  things: the faculty of faith, of energy, of mindfulness, of
  concentration, of wisdom. Yet if he has merely faith, merely affection
  for the Tathaagata, that man, too, does not go to... states of woe.</p>
</blockquote>

<p>On Vi:</p>

<p>When training Satipatthana it is not the objective to get well-concentrated, the concentration comes in succession and has its role and appropriate function. IE it also is involved as a causal condition for people attaching to certain states and that hinders progress.</p>

<p>Sati as a factor of Enlightenment, translated as mindfuless has function of remembering or keeping in mind, re-cognizing. Mindfulness of physical and mental states arising of and within a body is a single theme for the mind, which will develope concentration faculty no problem.</p>

<p>It seems to me that you could try paying more attention to arising and passing of states of "disliking", "wanting/liking", "sadness/despair", "judging/evaluating", "doubting" and "thinking/wondering" as well as "knowing", knowing ie when your concentration is low you can know it as "my concentration is weak", then maybe "disliking?;)" or "wanting" for it to be better or "evaluating" that it makes you a bad meditator, should note that your are thinking at this point and see where it goes from there. You see it will keep you within the theme of mindfulness of the body, conditioning victory.</p>
