My (26F) relationship with my mom (50SF) has been gradually crumbling

Hello! This is my first time posting here! This might seem like a rant and it is only my side of the story, so disclaimer: will be biased, will be very long, will have grammar issues, and will be a shit-show. My mom is a single mother. She brought me and my brother from an Asian country to the U.S. for us to have a better life. She's sacrificed a lot for us two and she lets us know about it almost any chance she can get. I am grateful for her. I really am. I wouldn't be here, living a better life than I would have lived if I were still in that Asian country. We're not poor, but we're not rich either. Just below the poverty line, although I'm not complaining as I have a roof over my head and food to eat. I even have a little cat I call my little brother (he will be relevant later). Although I can recall happy times when I'm with her, I can recall even more times that I am angry, hurt, disappointed, and/or disgusted with her. Her personality isn't the best. She's cynical, curt, has trust issues, and complains 24/7. I never not hear or see her complain. Never. Not an exaggeration. Moving on, ever since I was little, I was placed second and my brother first. I always remember when she taught him how to read and write in our language but never sat me down and did the same. I even asked when they were studying together if I could learn with my brother, but she shooed me off. I'm always compared to him too. How he's better at resolving issues (such as calling insurance, phone, and credit card companies) and that I was stupid and needed to grow a backbone. He's the older child and was always relied on first before I could gain any experience in that setting. This made me grow up timid, shy, and frankly a pushover. She rarely ever complained if my brother didn't do the chores, but when she saw me she would yell at me for being lazy and a waste of space. I commented on that fact and she said, "Well, he's a boy. You're a girl." Even if I got good grades she'd compare them to my brother's. Queue the traditional Asian Godzilla helicopter Mom back-light. I began to see her differently at a tender age of 14. Prior to that, during middle school, I had wanted to play soccer and begged her to let me do it. She complained and admonished me, that girls don't do sports or play games, that I'd get hurt, that it would be too expensive. That she had no time to be driving me back and forth. I even offered to take the bus...she said it's too dangerous for a girl, but my brother played football and she drove him back and forth. Bought him some equipment. Then he got hurt and she solidified the fact that I shouldn't be doing sports. In high school, all the hormones and the teenage anger built up. It kept building up. Through all the mental abuse and derogatory comments she gave me. To belittling my friends, complaining whenever I go out. Then complaining whenever I stay in. When I do go out, I had to text her when I'd get there. Who I was with. Where I was going. What time I'd be home. Then during the outing she would call me to ask where I currently was and when I'd be home. She told me to stop hanging out with other Asian kids because she didn't like their parents, that they were ugly, that they had an attitude, that you shouldn't be hanging around with Hispanics or Black kids. All that built up to one night where I talked back to her and she banged my head against the door. I bawled my eyes out and she walked away. Never once acknowledged it or apologized for it. I will always remember this night. Later on in high school I wanted to adopt a kitten that needed a home and asked her if I could bring him home. She told me yes. When I did she was ecstatic, but after a while she started blaming me for bringing home a cat. That she would throw him out. That she didn't agree to it. It took me a very long time to get her to change her mind. He's my little brother and mental support. I was deathly afraid for him and for myself... Then college. My first time away from home. Away from her. She would come to visit me almost every 2-3 weeks. She'd call me almost every day to ask who I was with, where I was, if I was hanging out with a boy, if I had a boy in my dorm, or if I was doing bad things. Then one winter when I was home for vacation my period was off for a few days. She kept track of my periods by looking in the restroom waste bin...I didn't find that out until this moment happened. She was driving me home and started accusing me of being pregnant. That she knew I had a boyfriend. I was like...what the absolute fuck. My major allowed me no time to slack off, and it wasn't a major I voluntarily chose but was coerced into by her. I told her no and very angrily. She got pissed off, telling me she knows and that I was lying and a whore. That she raised a devils child. Few days later I got my period. She never apologized. She even called her friends and told them about it, laughing it off. I was absolutely livid. Those were the very moments that I have kept locked up in my heart. There are numerous other events, numerous other abuse, but I can't write them all out. Now come the quarantine. I'm stuck with her 24/7 because my hours at my job (I work part-time and go to grad school) were cut and school went online. It has been a miserable 3 months but I am lucky in many other ways...besides living with a she-demon. Here comes to light many things and I will keep them succinct. This one I was at fault for but I'm glad it happened because I got to know her true feelings about me. I was starting a conference call and told her I needed privacy. She came into my room as the call was starting and (I muted myself no worries) I blew up on her. I don't know what came over me but I yelled at her to get out. She was shocked for a bit and started pacing in my room. She left and after a few moments started screaming at the top of her lungs at me. Profanities, abuse, disappointment. Nothing new. But the one line that struck out to me the most was the fact that she said, "I have tolerated you for the LONGEST time. You ungrateful little shit." I don't know why that line rung in my ear as much as it did...but I know now she never loved me as much as my brother. Then today. Today cut my tolerance in half, threw it down the drain, poured Drano into it, and washed it all away. I was sitting down minding my own business and she comes up to me asking if I registered to vote yet, I told her yes. Mistake #1. She then pauses and tells me to vote for Trump. I tell her no. Mistake #2. (Also, please don't bring political opinions into this. It's not the highlight of this post; I respect yours so please try to be understanding). I then whisper under my breath stupid. Huge ass mistake #3. She heard and slapped me. Now, in comes in the dramatics! She starts yelling at me, that I'm an ungrateful, disrespectful, stupid POS. That I listen to biased news like CNN and don't do my research and cannot think for myself. I do not watch CNN. I do my own research (albeit lacking at times) and I try to think for myself. She watches FOX and Asian news. What made me snap and call her stupid was the fact that she had commented (a very racist one in which I will tone down) that Black people are targeting Asians and that they're dogs. That Obama used millions in vacation time while President Trump hasn't used all that much. BUT I DIGRESS. What made me write this post was the fact that I realized how she's manipulating me. I know that my knowledge is lacking; mostly in life. But I know she is trying to form me into a person I don't want to be. I can't have my own opinions around her, even if those opinions aren't well formulated. I just want to be free of her but my morals and fear are holding me back. She always tells me (and my brother surprisingly) that we'd throw her in a nursing home once she was old. That all this time raising us was in vain if it were. And I would tell her no, that I'd take care of her and buy her a house near a lake. That was my goal for the longest time. I still feel an obligation to do it...but I'm honestly at my breaking point. How am I supposed to cut her out of my life when I live with her and rely on her for many things? I am coddled. I am a grown-up brat. My car, car insurance, credit cards, banks, phone, etc. Almost everything have her name on it with me being secondary. I pay for everything except the car insurance and phone bill. I live in her house for free as well (I am very fortunate in this aspect). I pay for my own schooling. I never stopped to think how much she controls my life. I never stopped to think how unequipped I am for real life. I never grew a backbone. I never grew a voice. My career path wasn't something I chose myself. My life...isn't mine and my experience in life is absolutely and horrifyingly inadequate. Please tell me. Where do I go from here? How am I supposed to build up the courage to leave her? There's so many obstacles, money-wise too, that I am afraid to cross. I don't want to abandon her, but I also don't want to live knowing that I'll have to be with her for the rest of my life. Side note: I've tried therapy and it didn't help me. I couldn't voice my true thoughts. tl;dr I can't see a lasting relationship with my mom anymore and I need to find a way, either courage or life advice, to remove myself from her.