Is it selfish to establish boundaries with ageing parents?

Hello. I lived with my parents till i was 25. I moved out despite of their resistance and have been doing well since then. During my entire time with them they fought with each other, to the point that my mom left suicide note but decided against it because she didn't want to leave me and my elder brother behind with my abusive father. My father had depression for almost 10 years and it showed. I remember his violent outburst at my mom and how much we feared him. He also suffered from insomnia for the better part of his life. As kids we were so scared of waking him up when we used to go to washroom that we would crawl on the floor and did not dare to turn on the light at night. Even then he would scream and hurl abuses at us. Also for cultural context, I'm from India and my parents weren't stoked about me being born as a girl because dowry and all that. They both had decent jobs though. My mom thought it was a good idea to tell a very young me that my father never wanted to have me (a girl child) and had suggested to give me away to an aunt who couldn't bear kids. But that fact didn't surprise me at all because i could feel that everyday in his behaviour. My mom too was a big time misogynist. Her family like most family at that time and even to this day had the culture of giving special treatment to male child and consider girls as liability because eventually they'd have to be married off.
Cut to the present, I'm 30 and live on my own and have a decent job. I'm also gay. The childhood trauma and being queer in a developing nation wasn't a great combination so i had my fair share of anxiety and depression. Currently I'm on antidepressants and they're working fine. I'm out to my friends but not my family. I don't feel close to my family, i never felt any support from them as a child and i don't think it's going to make any difference even if they knew. I just don't want to do so much emotional labor for no apparent result. So after being pushed again and again for marriage, I've told my parents that i don't ever want to get married. They're still trying for it though but since I'm independent and don't live with them, they know they can't make me do it. Now, my mom came with a brilliant plan that if I'm not getting married, the least i can do is get a house on loan and she would leave my father and start living with me. When i told her i can't live with either of them, she started pushing me. She told me to ask my flatmate to leave so that she could live with me if I'm not ready to buy a house on loan. Let me tell you my parents are well off enough to have some land and two houses. She can afford to live on her own if she wanted to, but she wants to wrap it under the garb of helping me so that society doesn't judge her for not living with her husband. I told her that she always had problems with me throughout my childhood and now that i can afford to live away from them, there's no way I'm going to mess that up. But she kept saying that she will live with me, no matter what i say. So i told her that i had a bad childhood with them and now that I'm a adult, i no longer want to be with them. I'm ready to fulfill all my duties as their daughter but what i can't do is also sacrifice my adult life for something that have so many different alternate. She was furious at this. She started ranting about what an ungrateful child I'm. How I'm blaming my failures on them now... How my brother lived in the same household and has no complaints... How children on the streets too have a difficult childhood but don't complaint....annnndd her favourite phrase that she has been using on me since childhood..."you can't adjust with anyone, that's your demerit". Which is funny because i can literally be friends with an alien... That's just how open to new experiences I'm. Infact they have this complaint that i talk to my friends and even strangers wayyyy for than i talk to them....i don't know when it'll dawn on them that it is them i can't adjust with.