Just need to rant...

So I was in an abusive marriage for 3.5 years. Constant tearing me down and mental abuse and turned into physical abuse to the point of trying to kill me so he wouldn’t have to pay to divorce me. It’s taken me some time to get over and open my eyes completely to that and what all happened to me while I was married, now I have forgiven my past but have ptsd and my mother knows all of this. My ex in the end was abusive alcoholic and I try to steer clear of people like him. I was doing so great and then my mother met her soon to be husband and I feel like I’m losing my mother. I’ve expressed how I feel and explained everything to her but she’s so blinded by her version of “love” that I’m scared it’s going to get her killed. Her thing is an abusive alcoholic. First, He got mad at my brother (brother was not drinking just watching the game) mother’s thing was drinking and got so out of control mad that he attacked my brother. My brother may be 89 pounds compared to this 350+ man... this has happened multiple times and we’ve had to call the police both times.. nothing was done and my mother blames my brother. Then he banished me and my boyfriend, my mother invited us over for dinner and because I care for my mother we went and we were all having a good time my mother had a few coworkers over as well and when she left to take the coworkers home he snapped and started screaming at us to get out of his house and not come back. He’s now demanding we (my boyfriend and I) apologize for his actions the day we got banned. He says we are disrespectful and rude but all we did was eat like my mother told us to do. She made soooooo much food and is on a diet so she doesn’t like to have to much leftovers in her fridge. It was like a lite switch went of in his head and we didn’t know what was going on. Fast forward 4 months and my mother invited us to her thanksgiving dinner again made soooo much food and is on her diet still, we step one foot into her house and her drunk asshat demands we leave. Now my mother worked so hard on all of the food for thanksgiving and just wanted to celebrate with her children like a family, instead it ended up with my boyfriend stuck in the car while my brother, mom, and myself packed everything into Tupperware for myself and my boyfriend and him screaming at me and my mother the entire time. And the night ended in tears and now my mother is again taking up for him and saying we need to apologize to the dumbass for him ruining our thanksgiving?!?!?! I told my mother that we won’t be back. We will not be apologizing to a drunk and if she wants to celebrate Christmas with her children that it will be at my house but the drunk stays home. He is not welcome in my home and I will call cops if he shows up. I feel wrong for doing these things but I felt like I had to do something, my older sister supports my decision and keeps telling me it’s not selfish to remove him from our lives but I fear it will end up with my mother injured...