Guess what? I once was a copy editor, and so I definitely know how you feel. The goal of copy editing is to create perfect copy, and when we fall short of that goal, we can feel pretty stupid. But hardly a day goes by that I don't notice an error in a newspaper or a magazine. Every copy editor is making mistakes, and chances are it doesn't cause them much of a problem. If copy editing doesn't give you any satisfaction, then stop doing it. I did.

You definitely need people to talk to and be honest with. If someone says something that is hurtful, let them know in a calm way that it felt bad. People aren't trying to ruin your self-esteem, they just assume that any correction that they make will not be harmful. The more honest you are with people, the better treatment you can expect from them.