I really feel for you, this sounds like an extremely difficult situation. Unfortunately it sounds like there may be mental illness involved, and DBing is not really geared towards solving issues like that. And you can't really encourage him to seek help because he will just view it as nagging. If there's a mutual friend or family member that he respects you might talk to them to see if they can encourage him to get help.
That said, DBing can at least help you. The techniques will help you to detach and GAL with or without him and it sounds like you really need to separate yourself from his storm right now.
Me: 58 w/ S16, D22, D25 Current R: 4 years Previous M: 21 years; BD: 06-14-12; S: 09-10-12; D final: 03-17-14; XW:56