How should I deal with very negative feedback from some students? I am a lecturer of a computer course in a university. Two months (almost 20 hours) of lectures have already finished. Very recently, I planned to get some feedback from my students on my lectures.

I asked a couple of questions such as 'how motivating the course is ...', 'how do you rate yourself on topic X', and many more.
I also asked them to fill a comment box that would improve my teaching.
This feedback is open to all the students registered for the course that also includes those guys who never attended a lecture.
I used a Google form for the process and made the responses anonymous.

From the multiple-choice feedback questions, I learned a lot of things and actually, I got to see a few strengths and weaknesses of my lectures. However, the comment section of the feedback has made my life difficult for last few days. I am really disturbed after going through and thinking over a few comments.
Here are some examples of comments:

You do not teach what is in the book. Plus, you ask very difficult questions in the test. What do you want to prove?
Who recruited this guy to this university?
One should learn how bad to teach from this faculty?

At the same time, other comments look like the following:

He is the best in the field.
He explains the most difficult concepts in a very simple and clear way.

The students (all are undergrad) are pretty straight-forward and have been really not-so-formal about it. I don't want my frustration to reflect on my lectures. I am new to teaching and that is why I wanted to get feedback.
How should I deal with this? Is it normal for an early-career academic?
Update:
After going through the comments (discussion) on this question, one may find out that the students are confused, probably during the discussion. However, there are two more points one should consider:

Since the feedback is anonymous, it is difficult to track a student and personally talk with him/her regarding his/her confusion.
If the students that have given such comments just came for one or two lectures, and they are judging the faculty's strength just based on that, then it is unwise.
If the above (second) point is true, then the concerned instructor should not take seriously those comments.

Is it a good summary?
Could I get some suggestion on how do I manage in such time? Is it normal for a early-age academia?


No, this is common for academics of any age. Anonymous evaluations are notoriously a valve for students to express their dissatisfaction without having to be reflective, fair, or even truthful about it. If you ask for anonymous feedback, you will need to be prepared for things that you don't want to hear. This can include very harsh judgments of your teaching quality, ad hominem attacks, or even tangentially (if at all) teaching-related comments to your person, your appearance, etc. Browsing Ratemyprof will give you a good idea what kind of statements students are willing to utter about their professors.

How you "manage" is by keeping in mind that (a) what you read is likely not the opinion of the silent majority of students, (b) that even the students that actually post hurtful feedback will often not really feel like this about you, but rather be frustrated because of a bad grade, a bad experience with your school in general, or just a difficult time in their life, and that (c) in reality, most teachers get a wide range of feedback from very bad to very good.

Also note that especially in smaller classes there can be tremendous differences between years, so having a bad evaluation in one year can still lead to a better evaluation in the following. Further, I have taken to basically ignore any feedback that has been mentioned only once or twice, and only start to take a specific complaint serious if it becomes a pattern.

TL;DR: In short, you will need to learn to not take the feedback personally.