New rule: don't look at your evaluations until you've taught another (different) course.
Every time I look at my evals I get depressed for several days. I know that they're supposed to be constructive criticism, that they're actually not that bad (really only a few negative comments), that people who have something negative to say are more likely to do the evaluations (only half my class did them), and that people who get lower grades give lower evaluations, but I still end up feeling like I am not only a bad teacher but a bad person. It just makes me feel awful -- and I just glanced at the comments.
I do know I have a lot to work on as a teacher -- I'm pretty disorganized (getting better) and when I give an assignment for the first time I tend to make the instructions vague (getting better at this too).
But I've got to quit reading the comments right when they're emailed to me.