How to handle mom who requires more care then I can provide?

My mom is choosing to remain in her home, she has cancer & other illness. She’s been in & out of hospitals, rehab, etc & all the medical pros who have seen her in the hospitals & those nurses who have seen her @ home all agree that she should go to assisted living due to her weakened state & because she lives alone. She has fallen x2 which ended her in the hospital ER. I am her only child, 56 yrs old & lost my job 2 yrs ago. I am literally living check to check & have taken 2 part time jobs to keep me from being homeless. I’m a dog walker & Uber delivery driver. Between those 2 jobs, it has me working 7 days a week, often times from 12noon to 8-9pm. By the time I get home I am exhausted. I don’t sleep well, often times staying up till 4-5am, then getting up around 11am to start my work day. I try to get over to my moms house every other evening to empty her commode, do laundry, clean the house & make my mom something to eat. During the week, I get her grocery shopping done. I can only stay a few hours at a time because it has become very stressful for me to be in my moms home. She keeps the heat on very high, 80-82 degrees. I have high blood pressure & am very sensitive to extreme heat so I have to turn it off when I’m there. My mother gets very upset & says “I’ll freeze if you turn it off”. I tell her “if I leave it on this high, I won’t be able to stay”. So I turn it off so I can do what I need to do. I have tried & tried talking to my mother about going to live in an assisted living apartment but she becomes very angry & will start crying saying “where will I put all my things”? I tell her she can bring some things w/her, she doesn’t have to leave EVERYTHING behind. But she refuses and says “you’ll have to help me more”. I tell her “I can’t come by anymore then I’ve been doing because I have to work”. She calls me sometimes 10 times in 2 hours, minutes apart in a panic leaving me messages saying “you need to come by & empty my commode because the caregiver didn’t come today, please come now and you can go back to work ok?”. Or she calls and says “the caregiver didn’t come today & I haven’t eaten all day and I’m hungry, please bring me a burger or pizza”. “I don’t have any water in my water bottle, please come & bring me water, then you can go back to sleep”, etc. I’ve had lived at home w/my parents for most of my adulthood & after my dad passsed away in 1991, so I have only lived in my own apartment since 2012. For 5 years I’ve been on my own and my mom has been miserable. She always tells me “your not married so why did you have to move out?”. Unbelievable that she feels a daughter in her 40-50’s should still live w/her parents. She doesn’t believe that it’s unnatural to raise your children to become dependent on their parents so as not to allow them to live on their own. This has always been an issue for my mom. She knows I’ve always struggled w/making a living & has always helped me out financially when I’ve needed it, but will hold it against me whenever she has done that. She KNOWS how hard it’s been for me to keep my head above water & to keep a roof over my head but she doesn’t care. She has become very mean at times, always bringing up the past and is constantly shaming me into doing things for her telling me that “I would never talk to my mother the way you talk to me” or “I don’t care what your friends did w/their parents (when the parents got sick & needed to go to a nursing facility & not expect their children to quit their jobs & become the parents caregivers), we’re different, we don’t believe in nursing homes in our family, that’s for people who don’t have any family.” She often tells me that I should quit my jobs, move back in w/her & get the state to pay me to take care of her. The thing is, even if I were to do that, when she dies, her house will get taken by the reverse mortgage co she has her loan with, I won’t have any $ and/or bad credit & wont be able to find an affordable apartment (like the one I’m currently living in), so I’m very afraid I’ll become homeless. Still my mother doesn’t accept that. I’ve gotten to the point where I REALLY am avoiding spending any time w/her because it leaves me extremely upset, almost like I’m going to have a stroke or heart attack from all the stress she’s causing. She only gets 20 hours a week for a caregiver to come 4 hours a day, 5 days a week. She has no money to hire any other nurses or caregivers to add more hours to that schedule so she’s basically alone 20 hours a day, and all day Sat/Sun. She gets $700 month SS & SSI.