Family conflict and seeking guidance, assalamu alaikum

Assalamu alaikum. I need some advice and wanted to share my situation honestly. In 2013 my sister and I were taken by our father to our home country so we could learn about our culture, the Qur'an, and Islamic studies. We stayed with my uncle and his wife. During that time his wife repeatedly abused us, and my uncle was involved too. She made false claims against us, and without checking, my uncle would physically punish us. Once he beat my sister and me badly and kicked me. For months I couldn't stand straight. I had to pray sitting and even shower while sitting because of the pain. We had no phone, so we secretly borrowed one and called our father. When he found out, he removed us and arranged separate housing. Because we were minors, my uncle controlled our money. A few months later my parents visited. When my mother saw my condition she was shocked and cried. She cared for me and Alhamdulillah I improved in about a month. Not long after, my father passed away. May Allah be pleased with him. A few months later my mother told me my grandfather suggested she marry my uncle-the same man who had hurt us-and asked my opinion. I was clear and strongly against it, saying he had harmed us. Despite that, she married him. I felt deeply betrayed and angry. Even when she became pregnant I stayed distant. When she was unwell and crying while taking medication I felt sad, but my hurt remained. Over time he treated her poorly: he married another woman, failed to provide, and relied on her financial support even though she had orphaned children to care for. Later my family arranged a marriage for me that failed, and then tried to arrange one with a cousin, which I refused. Feeling I had no safe options, I sold some gold, bought a plane ticket, and left the country to stay with relatives abroad. After I left, my uncle angrily called demanding explanations. I told him leaving was best for my safety and asked him to send my belongings. Instead he lied to my grandfather, accusing me falsely of disrespect. That was my breaking point and I cut contact. I have not spoken to him for about eight years. Recently I wanted to visit my mother but could not face him. Even hearing his name triggers intense pain. I told my mother I would not come to the house unless he acknowledged the abuse, apologized sincerely for the physical harm (including the kick that still pains me), and stopped lying about me. My mother insists I am wrong, saying he is older and like a parent so elders have rights. I disagree-Islam does not permit oppression because of age. When she arranged a talk, he refused to accept responsibility, denied events, or told me to “get over it” since time had passed. His words felt dismissive. Because of this, when I travelled to a nearby country I chose not to visit family, even though it was only a short flight away, which hurt my mother. Now I struggle emotionally. I don't see my mother the same way and feel overwhelming anger and disappointment, mixed with guilt because Islam teaches kindness to parents. When I speak to her my unresolved pain sometimes leads me to say things I regret. I would be grateful for any advice on how to handle this-how to balance my duty to be good to my mother while protecting myself from further harm, how to cope with trauma and anger, and how to seek a resolution in a way that is in line with Islamic principles. Jazākallāhu khayran for any guidance.