I’m very sorry to hear about the abuse you’ve received all of these years.
Realistically, improvements happen when you are able to escape situations like that. The question is, is this in any way shape or form possible for you?
It is not your fault that all of these bad things have happened to you and you don’t deserve it.
I doubt that your mother is actually happy. I’ve never met an abuser who is. The pleasure people get from hurting others is short lived at best and generally they hate themselves because they are aware of the pain their actions cause others.