There is always a chance that the situation will change, but it will be difficult. When someone gets their heart broken it takes a lot out of them emotionally. A total renovation of the thoughts and a great deal of healing has to happen in order to get out of the "mental gutter."

Assuming he's over you on an emotional level, I can see why he's hesitant to go back to you. Not only does it take a great deal of energy to get over someone, during the healing process mental flags are set up to ensure it doesn't happen again. You broke up with him because he didn't have enough time to spend with you. From his perspective, nothing has changed. You couldn't deal with it before so why should he believe you when you say that you can deal with it now. To take you back he would have to regain his trust in you again. Once trust is lost, it is an extremely difficult thing to regain.

I would suggest that you evaluate the current situation. By continuing to have a sexual relationship with him you put the ball in his court. If he still has residual feelings for you, every time you sleep with him he gets his fix. He doesn't have to give you up but at the same point he doesn't have to take the risk of getting his feelings hurt again, thus he's able keep himself closed off.

If you're really unhappy with the way things are there are only three things you can do - leave him, keep things as they are now no matter how unhappy it makes you feel, or give him an ultimatum - All or Nothing! When giving him an ultimatum don't go about it in a mean way, stay calm and gently tell him that you are willing to compromise to work things out. Express your love for him and let him know that if he gives you a second chance you'll try not to hurt him again. This puts him in the position that things will have to change or he might loose you once and for all. Of course by taking this approach you're opening yourself up to rejection. It can be a nerve racking experience but one you might have to take if you really want things to change. Be confident, display self discipline and hope for the best. Life works in mysterious ways, if it was meant to be it was meant to be.