Guess that might be a long post.
I'm 24 now, right after shitty college with useless diploma,  and during pandemic I lost different jobs few times, I even moved to abroad to find better life, but I ended up going back and with little debt. I had to go back to my hometown, where my grandparents still live (they're 85), me and my mom were visiting them once or twice a month (taking turns, we lived in different cities, quite far away).
When I was abroad my mom told me she can't do this no longer, bc she's got cancer and having chemotherapy, overwhelming work and taking care of grandparents was to exhausting for her to handle. So she asked me to be back and live with them. I agreed bc of economic results.
Mentally I wasn't in a good place at the time, all the college things, finances and handling my own life was difficult. And soon after I started to live with grandparents I found another difficulties. First, it's a town in the middle of nowhere with no job and nothing to offer, nothing to do (plus I don't know anyone there). Grandparents are hateful and show it every day, to everyone and to each other. Eating three times more than they supposed to and mourning that I'm not feeding them more. Stealing my things when I'm not home. Breaking them. Almost every second day I have to convince myself that I'm just a human, not a piece of trash, as they call me. It happend to her to be physically aggressive to me. Or call me a whore. 
I wish them to be dead, so badly. They (especially her) make my cry, sad and same hateful. Sometimes anger takes over but I'm trying my best to fight it, otherwise I'm scared I'm gonna hurt someone, sometimes I'm hurting myself just to get rid of this feeling. Grandpa is usually calmer, he's just doing nothing all day, drinking in his room and sometimes being verbally offensive. Grandma is worse she's despotic to both of us. She's literally screaming at people on TV and looking into our stuff, throwing out things she doesn't like (ofc someone else's things). Wherefore I'm not allowed to keep my clothes in the wardrobe, so they are in the boxes. During winter I wasn't able to heat. I can't have cosmetics in the bathroom, so they are all in my room. Which causes a bit of a mess, which is another problem to her, so when I'm out she's throwing them out (I have plants and some of them already disappeared). 
And I'm doing everything at home. Cooking, cleaning... I can be cleaning just to one of them enter the room to make a mess (it happens usually with the kitchen and once one of them shit on a carpet). I'm not pedantic but I like when rooms we all use are clean. I can't stand dirt, leftovers on the floor and spilled juices.
When I'm breaking and calling my mom she tells me it's my responsibility to stand it now and I suppose not cry, they don't mean it, they're just old and bored, and not mentally well, "just ignore it".
Last year my old friend asked me if I would like to write high school exams again to have better score for med university. I agreed but I have no power and conditions for learning, and I need over 80% on chemistry and biology to be at least considered as a student. 
I badly want to leave but analyzing opportunities it's shot to the knee. I had hard time living by myself working and studying at the same time, sometimes I slept 4hrs to keep up with everything, and I was still living from month to month with no savings bc I had basic payment. 
Now few times a year I leave country to work abroad for two-three weeks (in the job I hate tbh) then I'm back for 2-3 months and all of those money are usually spend on their food. I'm tired and helpless. I want to sleep and never wake up. I'm working hard to get nothing than punches into the stomach. I'm writing this because I'm going back home in two days and I'm not ready. 
If I leave, my mom will be angry with me and she's really responsible so I know she would overworked herself to death to keep her and their lives somehow. 
Staying will kill me, leaving will ghost me. I feel like if their life will continue, mine will never start. At this point I thought I should be moving mountains but I barely keep up. Out of hopes and energy. Ripped off independence and personality.
I don't know what to do...