I don't understand either, and that is my biggest problem. I've said this to him, but he can't give me any answers. He said he is very self-destructive and knows that in time he will probably regret this, but still he couldn't committ. I felt like I gave him ample opportunity and offered him support. It's extremely frustrating, as what we had was rare and special.
I can only guess he's going through a lot of life changes at the moment and everything is getting a bit much for him. He has recently left college and there is a big lifestyle shift there.
It just feels wrong.