Lisa I'm sorry you find yourself back on the shitty part of this rollercoaster. I agree with those who say he needs to be treated like an addict and that only he can help himself. One thing I would urge is that you try (both of you) not to get into the slanging matches that were occuring before his most recent return that can only cause more damage (but I know it is easier said than done). You do all the trying different approaches and the changing for the better now it has to be Bs turn.
Me 43 XH 45 M 2.7.88 Divorce 7.10.09 Kids D20,S17 & D15