Trying to have a relationship with someone whose brain won't allow him to be happy is an exercise in futility for you. Project yourself 2 years from now if you "stayed" with him - and I put that in quotes because he has 100% control over being with you or not - in 2 years, you will probably have endured 4 or 5 breakups and would be kicking yourself for wasting 2 more years on this person.

Take some time away from dating but when you do begin again, don't go over old ground. He is someone who wouldn't even be a very good friend. He needs help you can't give him.