I think you should tell him that you aren't capable of "just being friends" with him. At least not right now. Tell him, while it's nice that he wants to remain friends, it hurts too much for you. It's selfish of him to expect you to keep a connection that you're not able to deal with right now. You're not evil; you're human.

I understand not wanting to be cut off from him. But you can't make him love you "that way." It takes time to get over someone you really love, but it's no good if he doesn't feel the same, and you're only hurting yourself if you're seeking a relationship that isn't going to happen.