Alcohol dependent father, emotionally unstable mother

My parents are 70 and 63, they've been married for 33 years. I recently moved back in with them because I worry about them, and want to support them financially and in whatever other ways I can help. It also works out better financially for our family to live together. Moving out is not an option. I'm 29 but asexual and aromantic, I have no desire to go meet someone and "start a family of my own". My parents are my priority and I care for and love them deeply. But living with them has magnified their flaws tenfold. And I'm not saying I'm without flaws. My whole childhood my parents have always been fighting because of my mother's insecurities and stories she makes up in her head, her jealousy and her bad temper. She has struck my father a few times as well in her rage. She would also spank me for talking back at her, until my backside was blue. She would then have me show my blue backside to house guests to show them how naughty I was. The humiliation infuriated me. During fights with my father she would sometimes also just take off, get in the car and leave. One time she did this I tried phoning her and asked her to come back. She told me she didn't want to live anymore. I was 8 at the time. Because of this fear I had of her leaving, I slept in their bed from little until I was 10 or 11. She treats my father badly and talks down to him, she'll be bitter and cruel, and if he just once snaps back with the same attitude then she uses that as justification for why she talks to him like crap. She's quick to point fingers at everyone else but never acknowledges her doing or part in the problem. She loves me fiercely but she also is very self-centered and stubborn, and has a bad attitude when you confront her on her narcissistic traits. Loves playing the victim. My father has an alcohol dependency priblem but will never admit it. No matter how many family fights there have been because of it. He isn't violent, we just don't like it when he gets drunk. But despite all the turmoil caused by alcohol, he refuses to acknowledge his dependency on alcohol. I mean he will drink anything he can find that has alcohol in it, even if he doesn't actually like the taste. So many drunk holidays, Christmasses, birthdays, etc. He thinks it doesn't matter that he has too much to drink, in fact he denies having too much to drink. But somehow it always has and still does upset me. I hate it when he's drunk. He also has a short temper but has never hit me or my mother. He just gets angry at himself and sometimes us for stupid, petty things. I think he's having difficulty accepting that he is getting older. But we clash on many opinions, especially when he starts saying racist or sexist things and I call him out on it. I'm always the a-hole then, who is just going against him to spite him (in his mind). He doesn't believe the things or facts I tell him, but he'll believe it or anything else for that matter when it comes from other, less reputable people. I resent them. I don't ever want to be like them. And I feel guilty for feeling this way about them. A part of me thinks that I'll find peace and relief one day when they're gone, though I know their deaths will devastate me so I don't wish for that day. I feel like a bad daughter for even thinking this way. I don't know if you'd call what I have separation anxiety combined with trust issues and childhood trauma. I know many others have it worse. How do I cope with my situation?