Emotions can sometimes get in the way here. If you are close to someone and then lose them as a close, intimate lover it can be hard to relate to them at any other level. I think it is easier, however, if you were friends beforehand (certainly always was for me), assuming the process of break up is not so traumatic as to cause the loss of the friendship as well.

Distance may help. Get away from him, find new people to talk to and hang out with, and let things take thier course. In time you may find he wants to be friends again.