My mother is insane and so is my father

My mother is the craziest person on this planet, an insane woman. I'm 21 rn and this women doesn't have any boundaries nor basic common sense. For starters she isn't right in the head, she hits people, my dad and me, like choking, pulling our hair, hitting our head on the wall, kicking me and stuff, and it's got to the point where everyone's so paranoid in the house, my sister can't sleep without the door locked. If my dad is at home she finds every reason to fight wid him and this goes on the entire day, same wid me, she has crazy anger issues so if a fight has started she doesn't stop, comes into my room every 30 mins and rants the same shit again and again, even includes stuff I did since 8th grade like normal teenage stuff being rude and others but that's normal and now I can't change coz I've lost all respect towards her. And when I make her realize her behaviour she outright denies it or makes it look like it's coz of me she does this.

A week ago I begged her to stop fighting so much as it's affecting my sister and her studies and she shld be protected and be in a healthy environment, none of my parents did anything, my mom has this over the top dramatic Ekta Kapoor serial gestures that boils my blood, she kept shaking her head and repeating the same stuff again and again like mad woman, not joking, she does this all the time, and she screams at the top of her lungs and keeps saying I want to die after every fight. I grew up listening to this so subconsciously I became suicidal as well, so I told my parents about this and they didn't give a damn. On the same day I told her that I didn't want to hear her ranting and complaining about my father and do not want to be involved in this, also said I felt like I was born to fix their issues, I felt so vulnerable that day, an hour later she comes into my room and tells me that I must tell my dad to be a better man as she had seen in "movies" that children solve the issues, that was the day I realized that both of them aren't the parents they potray themselves to be.

I don't understand why parents can't be better for their kids, even my dad he's the worst, if she's hitting me or screaming for hours at me for no reason, he doesn't come protect me, for him as long as he's safe he'll do nothing, one day he stood up for my sister but when my mom started screaming and hitting him, he screamed at her that it's her fault, is that what parents are supposed to do.

And it's so confusing wid them, they're either too good or too bad, that way I can't hate them completely nor love them, it's like a light switch, no middle ground and everything they do is breaking me mentally, feels like I'm on survival mode all the time. There's so many things that they've done that's way worse than this but the post is getting too long.