This is going to sound weird, but love him as much as you can.
Don't get back with him, that would not be good for either of you, don't give into his whims, because that just makes him worse, and don't ignore him, as he will never learn.
The only thing left to do is that which love can provide: treat him in the most beneficial way for him and his life with NO REGARD for his feelings, welfare or personal attachment to you. Do what you need to do, out of love, in order to improve his position, make him aware and see the truth. This is going to be a hard lesson for him to learn, but if you really want the best for him, and I think you do, you need to give up what he thinks of you and do what it takes to go the hard line and, metaphorically, beat him around the head with his own stupidity.
You've tried everything else. The only thing less is the hard kind of love that leads to lessons, which can only come for when you care about someone to the exclusion of all else.
I guess the real question is, do you care enough about him to be the ♥♥♥♥♥ you have to be to get through to him?
