I remember when you posted back in June, people then gave you good advice and told you to lose the loser and that the guy was sick. Yet here you are again asking for advice again on the same subject. The problem is not him, it is you. He is up front and honest with you which is great at least you can't say he lied to you and use that as an excuse.
You say he has broken your heart again, that is not true, you have broken your heart again by continuing in this dead end relationship to no where. You should get into counseling right away because your problems seem to be greater than his. He accepts who he is and is up front about it. You need to find out what it is inside of you that makes you hang on to this unhappy situation as though your life depends on it. Marriage should not even have
You ask for advice?
I think your BF is being honest and I think you should be thankful that he is being honest w/ you about his feelings.