Miss, my STBXAH lost his mother to drinking, too. She was an alcoholic his whole life, and it eventually killed her when she suffered massive organ failure and shutdown. It hasn't stopped him from drinking, or making the false promises TO stop drinking, or thinking he CAN just stop drinking on his own--"Help is for losers", he has specifically informed me. I heard him, loud and clear.
He isn't going to stop drinking. He doesn't want to stop drinking. Stop taking care of him, because he isn't taking care of you. YOU take care of you, and let him follow his own path, no matter how destructive it may be. You can't change any of it. Don't even waste your energy, or love, or hope in trying to. Just keep focused on finding your happiness, and how to get there.