Bullying? Can i hit the bully?. Its been going on for 3 months now?

[anonymous]

You can redeem yourself by beating him? And the police will get involved on account for assault.
If that's the case, why not just get him done in for assault before you try to pull a Rocky Balboa.

Also, maybe, think of your girlfriend. If she's stressed now, doing something to stop yourself graduating, isn't going to help.
If he indirectly harasses you, I'm going to assume that's texts/facebook/twitter or some sort of social networking. If so, bring forth the art of "Ignoring".

For the record, you're in school. I don't know what sort of school you go to, though towards the end, I can safely say, reputation means nothing in terms of physical output. No one's going to care if did boxing before or not. (Honestly, even if it appeared it, I doubt anyone actually gave a damn if you boxed in the first place. Not that I'm trying to sound offensive or condescending. It's life, people rarely show what they actually think about others)
If you want rep, do well in school, graduate, go to college, University etc.
End of the day, if you don't. You then earn yourself a reputation of being a school failure, or a school drop out, or some other He-couldn't-even-make-it-through-school title.