@DataColour it’s hard being the child of parents who make those choices. I think it’s even harder becoming an adult, and particularly becoming a mother, when you’ve had the sort of childhood you had.
Mine was not completely dissimilar, although the abuse was towards me and initiated by my mum, who used to hit me herself and also force my dad to beat me. (There’s much more, but that’s one thing that’s really stood out to me since becoming mum to a daughter myself.) Dad would cry while he did it. Like you, I assumed it was quite normal. It really wasn’t.
In the last decade, when I’ve tried to raise the subject with Mum to see if she would do anything differently if she had her time again, she would always get angry and defensive. Me being upset as an adult, about being beaten and emotionally abused as a child, was my own fault, you see - I should simply not think about it and then everything would be fine. But of course you can’t not think about it. The way we’re raised affects how we relate to others, whether we’re conscious of that or not. Mum refuses to acknowledge the harm she caused or accept responsibility for it.
I look at my young daughter and just can’t imagine ever hitting her (even though she is, you know, a gigantic pain and endless test of my patience!) - never mind coercing an adult man to hit her. My mum and I have very different standards.
I’ve had therapy, on and off for the best part of a decade now, and will continue to do so. My parents are still together. I’m no-contact with my mum, but have a pretty decent, loving, and trusting relationship with my dad. The most important difference between them as far as I’m concerned is that Dad has admitted that everything they did was wrong, that he wishes he had done things differently, and he can’t understand how he ever thought it was normal himself. He’s genuinely sorry. Not angry and defensive. He knows it was all indefensible. (I don’t know how he reconciles his perspective with hers - it’s not my place to probe on that; I know he carries an enormous burden of guilt and I don’t want to make it worse for him.)
Neither of your parents sound likely to acknowledge the inherent wrongness of putting you through all they did. In your situation it’s probably sensible to keep very low contact, and to have therapy (I recommend it to everyone!), to help you keep your emotional distance and make some sort of peace with your parents’ current situation. You can’t fix them, and they don’t want to fix themselves. Your mum’s situation is very sad, but nobody can change it except her.
They might not be able to physically hurt you any more, but you should probably work out how best to protect yourself and your own family from any further emotional damage. At least it sounds like you haven’t carried on the generational cycle of abuse, which is something to be proud of.
Wishing you all the very best OP. This stuff is so complex to process, and I think being a parent yourself adds an extra dimension of complexity.