Have been through similar situation, when father has unresolved mental issues and does not want to accept and work on his fu*k all behavior/habits this happens. I don’t know what you can do legally, as your mother is not going to divorce him until he “dies”. But, keep your mind calm-steady be consistent and drop all dependencies on your parents.
It will be next to impossible but if you are able to figure-out the problem, you are capable to solve it.
You be sacrificing a lot so yeah, go workout that helped me a lot.
PS- find a good woman, it will keep you sane. Also save yourself so you can save your family. It sounds selfish but it is what it is!!
Remember- walk on a broken foot, leave no trace of your hands on anyone’s shoulder (anyone).