This is hard, really hard. I've been In almost the same spot(it wasn't clinginess that drove him away, it was extreme self destructive behavior). Really all you can do is give him time and space and wait for him to come to you. He still cares about you, I can assure of that, he's jsut having trouble dealing with your issues.

I understand though. I don't put my trust in ANYONE and hide things from everyone. A confidant is a terrible thing to lose.