I feel for you, I really do! What a heartbreaking situation

But as many have said - do reconsider trying to help him. Unless he's willing to help himself, no amount of pushing or pulling will do it. You can maybe hope to open his eyes to the fact that he needs help, but honestly - if the break-up of a good relationship and the loss of a good partner won't do it, I don't see what will. I don't know his issues, but to me he has serious trouble communicating properly, for one. He could be the man of your dreams, but if he can't tell you, not even when it really cracks down, what's bothering him and what he wants changed (i.e. work at actually keeping the relationship together), he'll be impossible to live with.

Maybe he can be a good friend at some point, when you're not that dependent on each other.

But be aware that you might possibly be wanting to help him, to make yourself feel better. When you're vulnerable there'e nothing like feeling "blameless and untouchable", as it were. He is actually treating you badly. You don't have to take revenge or be nasty, but there is no need to go around pretending to be friends. And being nice will not bring him back.

I really hope this doesn't sound harsh, I don't mean it that way. But it's very hard to realize what you want if you're too busy worrying about him.