I'm thinking about the fact that my confidence is so low.
What is the reason for your confidence being so low?
A coworker rejected my advances when I told her she had a nice ass.
Everyone has low confidence sometimes, but you shouldn't dwell on it or else you will never feel good about yourself. However, you also shouldn't sexually harass women like that. Telling a woman out of the blue that she has a nice ass is extremely rude and offensive.
But I enjoy sexually attacking people, it's fun.
You should not go around attacking people just to make yourself feel better. Try and find out what is causing you to feel insecure, and address this issue.