As a uni student, it's in my uni's rules that no drug consumption is allowed on campus.
Weed is a drug, a narcotic if you will, and while I have no probem with people who use it, don't act suprised if others don't care for it much and you face consequences for your actions.
Hell, vicodin "helps with the pain" doesn't mean I should be popping them like tic-tacs.
Anyway, consult a laywer, but expect it to stick on your record for ever. It sucks man, but next time, don't break the law. I'm sorry if that sounded overly harsh.