As-salamu alaykum - I can’t understand why people accept husbands abusing their wives

Long post, sorry. As-salamu alaykum. I’ve been depressed for a long time, and a big reason is my family. My mom has mental health struggles and growing up with her was difficult. I’m 23 now and still have to remind myself she isn’t always all there. I have three siblings: a little sister who’s delayed and very childish at 18 but with the kindness of a young child; a 30‑year‑old brother who’s selfish, rude, and has drifted away from our deen and morals; and an older sister who’s the only one who seems steady and has stronger values. My dad failed as a father. He’s drifted so far from Islam that I don’t think he fully believes in Allah anymore. That influenced my brother too. My dad hurt me emotionally in ways I don’t think I’ll ever recover from. As I’ve gotten older and started caring more about morals and faith, seeing how they’ve been lost in my home has been painful. I’ve been in therapy since February and on antidepressants since July. He’s abused my mom throughout their marriage. They married 31 years ago, and my brother came a year later. He’s verbally and physically abused her - once putting her in the hospital, leaving a scar on her forehead, and even going to jail. He abused my brother badly in front of us and hit me and my other siblings too, though not as severely. There were things I can’t forget: when I was small my dad threw something during an argument and hit me in the head by accident, and another time he struck my mom with a framed Quran portrait and smashed it on her head - the scream she made is something I’ll never get out of my mind. He curses Allah and swears in Arabic, calls my mom terrible names, and shows no remorse. He’s stubborn, thinks he’s always right, can’t take criticism, and treats people cruelly. There have been some good moments, and he thinks paying the bills makes him a great dad, but that doesn’t erase the years of damage. I promised to care for him when he’s older and tried to be a good son, even though the relationship has been strained. Recently we argued because my little sister got detention for oversleeping and irresponsibility. My dad told me not to bother her, but I spoke to her gently like an older sibling because nobody else disciplines her and she’s heading toward trouble. She cried, and my dad called me, swore at me, and even threatened to stop paying my school fees. When he cursed in Arabic at Allah and at me, I snapped, yelled back, and ended up leaving the house. My mom begged me to come back, but I’ve been ignoring him since. I can’t understand why my mom stayed. I feel it would be better to face financial hardship than the emotional wreckage we’ve all lived with. My dad once told us he wished we were dead when he was angry, told me to kill myself - things no parent should say. He doesn’t seem to realize how much worse he’s made my mom. She wasn’t always well mentally, but he’s made her decline over thirty years. What angers me more is how my aunts and uncles let this happen. My mom says they intervened many times, and he’d stop for a week or so, then go back to the same abuse. When my mom told my aunt that he was abusing her, the aunt said she should have patience in marriage. I can’t accept that. Their inaction allowed my mother to be harmed repeatedly. This kind of silence happens in our culture too often - people hope the problem will pass and then forget about the victim. My siblings and I thought about ending our lives when we were younger because of the pain. My older sister, who is married, still has trauma and avoids visiting because of how my father treats her. I’ve lost hope in my dad. He has no morals and expects Allah’s forgiveness without changing. He once had a tumor and said his duas and apologized, and after a car accident he did the same, but the behavior returned. I don’t know if I’ll ever have a normal life. I want a pious wife and children, but I’m scared - trust issues, anxiety, panic attacks, and the fear I might break down in front of my kids. I worry about how trauma will affect my future marriage and family. If anyone has advice on how to cope, how to support my mom safely, or how to find faith and healing after growing up in this, I’d appreciate it. Jazakum Allahu khayr.