Advice please.

My boyfriend and I have been together for going on 8 months. We were about to move in together because we felt we were soul mates. We stayed together very frequently prior this decision and things seemed perfect. Recently he brought an old friend back into his life that he used to party with and he started using drugs again (smoking pot/ dabs/ taking pills/ drinking heavier, etc.). I feel like everything I fell in love with is gone. He is so angry and takes it all out on me. We argue everyday, even when I'm having the best day ever; somehow he manages to turn it around on me. He constantly is pointing out everything I do wrong and telling me that I treat my soon to be service dog better than I do him. He demanded me to keep him out of the bed, out of the room, and show him less attention (because he thinks I treat him better than I do him, but I literally do everything for him). He is always threatening to leave me if he doesn't get his way and I cannot mentally take it anymore. When he is angry, he says anything and everything he wants, he even gets verbally abusive (calling me a fucking retard, dumb ass, bitch, anything) and lashes out. Help me please, I don't know what to do.