Mother-in-law is insane. What to do?

I've been with my husband for 8 years, married for 3, no children yet but TTC. His mother is one is the most difficult people to be around. She has extreme mood swings and often says vile things to anyone within earshot. Planning my wedding was a nightmare.

I've never had a fight with her because i try my best to smile and let it go. She has an explosive temper and if her son, daughter and husband don't call her on it, how can I? She often says rude and hurtful things in front of my niece and nephew and no one says a thing.

I've been seeing a therapist for nearly 2 years to work on my own anxiety issues and we've discussed my mother in law. She says her behavior can be considered abuse and when we have kids, well need to keep them away.

My husband acknowledges his mother is ill but seems terrified of her. He says he'll stand up to her when we have kids but i don't know if it's possible for him. I'm starting to question having children and even my marriage. We have to go to his parents' every Friday by tradition.

Should I tell my husband we need therapy? I feel so trapped in my own life. Any help is appreciated.