Are self-doubt and desperation a normal part of scientific writing? I am currently writing a research proposal for a PhD in a very interesting field. While working on the proposal I noticed that I run through the following (emotional) stages:


Enthusiasm: I think about the topic and am excited to work on it. I
start thinking about what I want to do and how I am going to do it.
Optimism: I do the necessary initial research on the topic and am
still excited. My interest in the topic grows and I am very
optimistic.
Self-doubt: I start writing and suddenly I am confronted with questions I can’t answer. I start doubting myself and think about all the things I don’t know. I start thinking that I am incapable of finishing this and that I really have no idea about the topic and what is expected of me. I try pushing through but am really hitting a brick-wall.
Desperation: I can’t get any work done because I don’t think I can do
the work. I get depressed and angry and make no progress.
Mild optimism: I somehow get myself to work on the project again. I
start with the easy parts and just push through until it is all
done. I start thinking that it wasn’t all that bad and that the
desperation really wasn’t necessary. While I am mostly satisfied
with the outcome I still doubt that the result is the best I could
do.


Looking back at my time as a student1 I realized that I run through those stages every time I have to do scientific writing. While I am never quite satisfied with the result, I have always received great feedback and excellent grades from my professors.

Now that I am thinking about doing a PhD I am starting to doubt if I am the right candidate for this because of my difficult writing process. While I know a few people who run trough similar stages I also know people that are enthusiastic throughout the entire process and love writing scientific papers. Maybe those people are more suited for PhD programmes than I am.

So my question is:
Are self-doubt and desperation a normal part of scientific writing?

Related questions:
Can I still be a good researcher if I constantly doubt the quality of my work? 
Is there something that I can do to mitigate this part of the process?



1Not sure if this is relevant but I have written several smaller papers in class, two bachelor’s theses and two master’s theses (in different academic fields).
I start with you related questions: 


  Can I still be a good researcher if I constantly doubt the quality of my work? 


You got it the wrong way. The real question is: Can I be a good researcher without constant doubt of the quality of my work? And the answer to this question is no. You should always question your work and and strive to make it better. Doubt is an integral part of research. But beware, that you should come out of this with "yes, my work matters/is of good quality/is relevant…" often enough either by your own conclusion of by feedback of others.


  Is there something that I can do to mitigate this part of the process?


Not sure, but you do not really need to. Please read this thread to see how to deal with insecurity and doubt as a researcher. You'll also find that the answer to


  Are self-doubt and desperation a normal part of scientific writing?


is most likely to be yes for most people regarding doubt and partly regarding desperation (assuming that "scientific writing" and "doing research" are quite similar in this respect). As Nate Eldredge notes, you should critically ask yourself if your self-doubt is close to be "pathological". I am not qualified in any way to give advice on how to diagnose yourself but you may want to read about the impostor syndrome.