I went through this my first year in college too. Agree with most of what is said in spirit. It is pretty rough going at the time, but you will be better off calling off the relationship now. You might be surprised once you start telling people at college that you broke up... there may be other women that suddenly show up on the radar that you didn't anticipate now that you are single. For me, we broke up sophomore year in college, saw other people, stayed friends (i.e. saw each other occasionally over holidays and summer break at home). I couldn't stand the fact that other guys were banging her, but now I realize that stuff is stupid and not important.
After college ended, I think that she had interest in getting back together and giving it a shot. I had met someone else that was a perfect match for me (even though I truly thought my HS girlfriend was real love) and never looked back. Don't try to force it and hold onto the relationship at this point. The cliche is that if it is meant to be, then it will happen in the long run. The other cliche (which is false) is that there is only one true love for each person. You can have a life long great relationship with more people than you think (I have been married for 27 years). The key is have the right conditions for that relationship (i.e. both parties committed, both living in the same place, both content and not looking for something else missing in the relationship).