Not too much anymore. I used to, though. It basically paralyzed my progress on my comic...
But,I became extremely sick a few years ago and am gradually getting to the point where there are days when I can't pick up a pencil. I cherish the days when I can finish up a page and try not to look too critically at my work. These days I do most of my self-criticism in the early draft stages, where making mistakes is expected and just part of the process of refinement.
Ugh, I wasn't worrying when I should have been worrying, and now I've taken to worrying too much XD
Okay, maybe not that much. It's just, because I didn't pay as much attention as I should have, I've burdened myself with the job of having to much to fix now XD So, I worry how much of this I can get done before I'm too old to complete it.