I know enough to know that "proper bike fit" is something that shouldn't be worried about when your intended use is riding on campus and light commuting.
I also know that there are way more people out there riding a frame that is too small than people with one that is too big. Therefore chances are, the OP's bike isn't too big.
I also know that if one can stand over the frame comfortably, all other fit issues can be taken care of by adjusting seat height, seat setback, seat angle, stem height, stem length, crank length, and so on.