Listen, to all the people saying that you should not stay around and dump him, the guy in this situation seems to be stuck in a rut and WANTS to get out.
I'm not saying that it's woman's job to stick around and change a man, by any means. GrandCosmos, if you feel exhausted and emotionally drained from this relationship, don't feel ashamed for wanting to end things. You should look after yourself first.
But, that being said, if you really want to make things work, I think you have a chance, because it seems like he wants to make a change, he just doesn't really know how. I know it's really hard to think of putting a focus feelings right now since you've felt like he's not paying any attention to you. And before you say anything, I think you should really put all your feelings out there, everything you've been thinking and how you've been hurting. But tell him why you want to be in this relationship, and remind him why you're here in the first place (it may seem obvious to you, but if he's really low, he really needs to be reassured). And then, ask him if he really wants to make a change, and this is where you come in as a partner. If he wants to, but is scared/unsure, you can do some research and make some suggestions.
If he doesn't want to do anything, then that's fine, he made his decision, and you can leave knowing you tried all you could. But before you give in, be there for him, even when it's really hard for you right now, and listen and help him change, if that's what he wants as well.