it would be easier on you to simply demonize him: hate him unconditionally and forget the fact that he is also a human being you once liked and respected . that sort of reaction to anyone we disapprove of is quite fashionable these days. But I think you are doing the right thing to both cut him off and feel the pain. it’s best for you, and the best for him. I don’t know whether I would have the guts to do that, and I admire you for doing so.