[Twinge]

You can't get over a 3 year relationship in a couple of months, probably not even a year. Commitment is like that, it stays with you despite their presence. And I get the feeling. It can be incredibly painful.
You're forced to be in this place where everything reminds of you of him. With time, you get stronger with that pain. That's what I learned through personal experience. Everybody says Time heals everything, and it's true.
The point is to accept what happened and to stop thinking about him (stop the thoughts from coming back and signifying what you lack), make some valid changes in your life. Maybe you're back in college, but that doesn't mean you can't gain new hobbies, search random errands and hang out with people that don't remind you of the past. This is possible, and it's maybe one of the best options for you to heal right now.
It's time to start thinking about yourself. Get back on track. With life, with everything. Obviously, if it's what you would like. Be patient. A long struggle is definitely worth it when you're finally healed and look back.