I really struggle with that feeling of helplessness. That's why I really try to get my blogs, and even myself, to point to the positive and look at all the inspiring things that are happening.
Generally I finish a first draft in 2-6 months, then I set it aside for a while so that when I come back to it I can read it with fresh eyes and figure out how to improve it.
Some people take 10 years to write a book and some can do one in under a year.

