Did I make the right decisions here?

This is in a professional work environment. I was interested in a guy who responded. Nothing arose between us; we hardly knew each other. I saw him do some pretty jerky, immature things so I stopped liking him. This made him look dumb so he retaliated by deliberately approaching & haring me. So..#1 I avoided him at all costs. #2. I ignored him when he accosted me. #3. Finally, I couldn't take the harment & reported him #4. I had made some accusations which were wrong so I apologized for those. Outcome: No one believed me. Guy got away w/everything & I'm left w/a lot of anger & vengefulness. Did I not make the right decisions? What could I have done differently? Why am I left to suffer?