Most Helpful Girl
It sounds like he doesn't know what he wants. Long distance sounds like it was easy for him because he could have his cake and eat it too, but now that you're physically close, it got all too real for him. My advice is to stop hooking up with him, and refuse to give him any emotional or physical support until he decides what it is he wants and whether he wants to be exclusive or not. Don't settle for a non-exclusive relationship when that's what you want, just to satisfy him and "keep him" because if he's worth it, all he'll want is you.
People are very different IRL than what they are at a distance so please, reevaluate.