Advice for 24/7 care, please?

I live in, with a lady of 93 and my 6 year old daughter. I was originally cooking dinner for her and her husband, but she lost her husband in May so I moved in as I was desperate to leave an abusive relationship and she put a roof over my head, for which I am grateful. I have never been a caregiver before. She has very limited mobility and has had many health problems since, chronic diarrhea being the worst I've had to deal with, sometimes round the clock. She has become extremely attached to me and I now cannot leave the house for more than an hour before she calls me and demands I come back. I wash her, dress her, clean her dentures. I cook and do the housework. She won't sleep til after midnight and calls me very early in the morning, sometimes during the night. I'm extremely sleep deprived. I love her but I feel like a bird in a cage which often overwhelms me and I have panic attacks. The family occasionally do a sleepover so that I can have a night off but they dont want to, so it's becoming rare. I get paid very little, just enough to get by and buy groceries. My alcohol consumption is too high, only wine, but too much, it helps me cope. I desperately want to get out but if I do she will undoubtedly be placed into a care home, and she really wants to remain in her own home. Because I dont have a "proper job" I am unable to rent a house privately, so I'm kinda stuck. I suppose I'm looking for advice on coping with anxiety and also hearing from anyone who can relate. Many thanks, Bex.