Toxic household

Sorry for the long post in advance. It has been going on for years and years, but the past 3 years have been awful. My family and I got into a really bad wreck and lost a lot.. My sister was suicidal so they shipped her off to a mental institute for a month. I was in school trying to cope while also having 2 parents who would fight every waking minute. Met a guy who just used me for pictures in the end. My sister came back and has never been the same. About 3 months later I discovered my mother has been cheating on my father. I was the only one who knew for about a month, then after that only my boyfriend and my grandma knew. Shortly after I got her to admit she had been talking to another guy and she told me after school that day we would need to talk. She told me that she had told the guy "We couldn't talk anymore" so that I didn't think there was something going on. Well I thought that was the end of her cheating. After that and even before (and still to this day) she has been nothing but mean. She use to hit me but that hasn't happend in about 2 years. She would call me names and talk down to me (and still does) tells me that I don't love her and that I don't care about her when in reality I will tell her I love her and she just ignores me or walks out the room. She won't hardly talk to me or have anything to do with me, and when she does its just to fight. She plays a front around other people and she acts like the sweetest person, but the minute its just my family and I she acts cold and means all over again. Anyways, 4 months later my dad went to the mountains for 4-5 days trying to find a mountain home and stayed with his friends while there... I found again not only had she still been talking to the same guy, but 2 more guys. About a month or two I finally couldn't hold it to myself any longer and I told my dad. One night everything was exposed but they still continue to act like it never happend. My mom doesn't really have anything to do with me and my sister anymore, she likes my sister better, I guess its because I'm to much of a realist. My mom tells me all the time that I will never be a good mother, that my kids will give me hell and ill be just like her. With school starting ill have to quit my job and she makes me pay for everything, but my sister, she gets pretty much what she wants. If my dad pays for me to get some freaking underwear its a whole fit and argument. I need out of this situation, I need a escape from this house, but I have to many responsibilities here. I won't get my lisence until November due to Covid. I can't get therapy or help because my parents would have to know and if I tell them the reason why it will probably be a argument and I'm still here with no help. Anyone have any suggestions? I have 1 friend and her household isn't good either, they won't even let her get her lisence so shes just stuck.. all I have is my grandma and things are complicates there as well. Any ideas? I need to be in a good environment but idk where to start.