It doesn’t matter if it’s a “revise and resubmit” article for a journal or a draft chapter to show to your dissertation advisor. There’s something anxiety-provoking about letting go of your work and putting it out there for the wider world to see.
One very brilliant client of mine told me how she had a similar feeling when she was 9 months pregnant. The baby’s room wasn’t ready, and she had so much more to do. She tried to will herself not to give birth yet. Luckily, her body didn’t cooperate. Now she tries to do the same with journal articles.
This reluctance to release one’s work is so common in academia, that it may well be the norm. In some cases, though, it can become crippling.