Villain with a ‘get out of jail free’ card

I feel so triggered and I regress to an emotional childhood state when I am with my MIL, like with almost no one else. She is my villain to my victim. It can be with her bad mouthing my husband and I to our preteen and teenaged kids while we are all sitting together in the same room. She tells them that we are not allowed to take their money (this has never happened), that they will not be bothered by anyone while we are gone when they are staying with her, etc.
My husband feels it is futile to say or do anything because he feels nothing changes, and he only hears about it from me as far as I know.
This Christmas I am at a point where I have raised her villainous stature to such a high level by giving her control over my thoughts and feelings. I could happily never see her again. I don’t feel she is welcome in our home to visit. Her get out of jail free card is that she won’t do or not do anything I say. She retorts that she will only stay away if her son tells her she cannot visit, because it is his house, not ours. And of course he won’t do that.

C: words said
T: this is absolutely unacceptable
F: Rage
A: hurl insults about her, give her control over how I feel, refuse to accept her as a member of our family, try to estrange her from us, use up excessive energy in all the negativity, feel like a toddler with a chainsaw, my discomfort of feelings of lack of control coming out as significant acting out, put my husband in the middle, also as a villain/responsible for my happiness
R: I behave absolutely unacceptably, have an unacceptable outcome of a rift in our family

Please help me to feel these uncomfortable feelings instead of acting them out. I really feel fear about emotional adulthood. I don’t feel equipped to feel these intense feelings of being out of control. I am having trouble seeing any positives in this situation. And I am so over living as a victim, blaming others for how I feel in multiple areas of my life.