In law issues!!!!

Okay so my SO and I have been together for 3 years, we have a 13m old daughter and are currently 23 weeks pregnant with our second. The issues I have had with my MIL include many things. She bashes me, bashes my SO, my family, talks poorly about my daughter. Like saying very mean and disgusting things. ( I'll add a photo at the end.) my SO and her don't even really have a relationship, it's weird. But he has a VERY hard time setting her in her place. It's caused so many arguments in our home. To the point when she freaked out on us the day my daughter was born, I told my SO. HER OR ME YOU CHOOSE. We completely blocked her after that, she has not seen her granddaughter once. She is absolutely crazy, and that's the truth. I do not want her in my kids life at all. But my SO still does. After everything she's done and said. I cry all the time because of what she says and the stress she puts on me. She is playing "nice" right now but it always changes and we're back at her bashing us. I'm so done and exhausted.