I'm sorry to have to say this, but maybe he just doesn't care about the relationship (anymore)? In the past, I've behaved in exactly the same way. I didn't quite know why, I just didn't have the willpower to go and see my girlfriend, I couldn't really be bothered. Now I know myself better, it was because I never fully committed myself in those relationships. I didn't really care about the girl, as horrible as that sounds. I got into it just "for the sake of it". Maybe I'm totally wrong, I hope I am. But you don't deserve to be treated like this. Talk to him about it yeahh?