I cant defend myself?

I feel that you need to muster up some more confidence in yourself. I know nothing of what extent to which you were bullied emotionally, but think about how for TWENTY years you took a lot of things personally, when perhaps it wasn't really that big of a deal? And as far as "hey fatty" goes, brush stuff off dude. There's really nothing to fret about stuff like that. Plus, just notice weird mannerisms of your friends and probe those too when you can. If anyone told you that everyone but you was flawless and that you're the only one with qualities worth making fun of, s/he was very very very stupid in telling you. Just relax dude... And whenever you feel worthless, go find some time for yourself, sit down and take a few breaths, and just think about who you really are get a hold of yourself.