I could have written your post, even down to how I thought about them through different phases of my life. Although they were not as extreme, and my father was basically just not involved, it all came from my mother.
One thing that sticks out clearly is me saying I was going to study really hard for maths, because it was the only subject I was bad at. My mother said 'right, let's see how long that lasts.' I don't know why I always remember that, she said so many worse things, but I think it was the first time I realised that it wasn't just that I was a horrible person/daughter, but that she was a bit crazy.
The constant judgement of other people. We can be driving past someone who has some shopping bags and they'll say "God, look at that moron with all their bags." WTF. It has made me both terrified of criticism and highly critical of others - thankfully, mainly in my head these days. But I find it very difficult not to hate people on sight. (Weirdly, when we're in my husband's home country, they think everyone is perfect? Very odd.)
They never taught me I had to wash more than once a week, or to change my clothes. So I'd wear the same clothes for a week, even as a teenager. I had issues with controlling my bladder and I remember I once peed myself at school and my shoes stunk of pee but my mum did nothing.
They never fed us adequately. It wasn't really til I got married that I realised that I wasn't eating enough. They'd always talk about these huge portions you get in restaurants and they'd end up leaving half and they'd always talk about how fat other people were because they ate too much food. My husband loves eating and it encouraged me to eat everything on my plate, and I realised that I actually felt full. And I stopped getting sick all the time. I used to get colds constantly, which I now realise was down to not eating enough. If I go to their house now, I'm shocked by how little they eat. My dad's lunch could literally be one of those mini pies or two mini sausage rolls, one biscuit and a tangerine, and he works as a builder. And he doesn't eat breakfast. My husband and I now bring food to eat in the bedroom because they just don't give us enough, even after seconds or offering to cook more.
Huge fights in front of us, my mum telling me she wanted to divorce my dad, not talking to each other for weeks on end.
The entire mood of the house was dictated by my mother's mood swings. If she was angry, we'd all have to go and hide. Then she'd be crying and we all had to be nice and tiptoe around her and tell her we loved her.
Just constant sneering at anything I wanted to do, so I stopped doing anything. I was really smart as a kid, read constantly, asked questions, good at everything, now I'm basically rubbish at everything. They treated me like I was a joke.
The worst time: she found out I was self-harming and she asked why I was doing it. I said something like 'maybe I'm just weird'. And she said 'yes, that is exactly what I think.' That was the first time I experienced depersonalisation and I think I have never really recovered from that comment. Everything I thought about myself, that everyone hated me, that I didn't fit in, that I would always be an outsider, was encapsulated in that remark. Who says that? Who tells their vulnerable, mentally ill daughter that she's weird?
Well, basically, I would say they didn't do any of the extreme stuff your parents did, they didn't lock me up or anything. My mother would actually do lots of nice things with us too. But you never knew how she was going to be, whether she would be nice that day or whether she would attack you for no reason.
When I finally stuck up for myself, she backed the fuck off and is now terrified of me. She will do anything to appease me. She still makes snide comments at times, but I just tell her to stop being silly and she shuts up. She even tried to start with me on my wedding day, nitpicking at my dress and saying I was lucky anyone would have me. I just sighed and asked her to stop her nonsense. Having that power over her is fucking great. For me, it's better than going no contact. Maybe it's not that healthy, I don't know.
She has no time alone with our kids, and she knows why. And it kills her, because my PIL have a great relationship with them. Sometimes she will say things like 'oh we could have them for the weekend' and I am strong enough to say 'no, I really don't think so.'
Good luck to you. It sucks having such a rough start in life.