Is it past time for my Mother to live alone?

My mother has gone from forgetting to turn a burner off to forgetting she is cooking at all and goes to bed. I live with her now so I try to keep her out of the kitchen by doing all the cooking but it was her hobby and she won't give it up completely. As long as I am home I have not stopped her from cooking but I do keep watch. Now I am finding red hot burners on in the middle of the night or when I wake up at six am. She places the pot holders and dish towels so close to the burner that I have walked into the room a couple times with the dish towel brown and black ready to ignite. She burnt up a new set of pans within a month or so. they were so bad the teflon was in my scrabbled eggs. I have talked to her about this but it makes her mad and she calls me a liar. However other people find it to. Then a day or two later she may be asking me for more help in another area of her life because she can't do it herself. Her health has been poor for about eight years with strict lifting and bending restrictions. Several surgeries in the last eight years. Each one seem to age her more. Her back has her unable to get around much. She has fallen and had to have surgery on her knee. I have been doing everything that needs done in the home, yard, errands, etc for years.Until this last year or so I also worked. Another problem is because of the pain she has all the time she is now addicted to Vicodin. I find it does not matter how you may become addicted the results to that person are the same. It makes her mean, angry, depressed, over sensitive and she does not reason like before. It changes her reality. Its really bad if she sleeps past time to take one. She goes into withdrawals within two hours. This will make her sweat, ache like she has the flue, vomit and just be mean. She tells me she does not like me and more I can't write here. Sometimes she will do this for a few days and then when she gets me in a place where I can't walk away she does it until I can't take anymore. If I respond badly she points a figure in my face and tells me
" see I told you your insane" . It is like living in the Twilight Zone, nothing she does during that time matches reality. I don't sleep much since I have been finding red hot burners on the stove in mid night or early AM. If I hear her get up I can't go back to sleep until she is back in bed and I check the range.
She also leaves food out like mayonnaise, meat, eggs, etc.overnight. Its so warm when I find it it has separated and is warm to the touch. I found she had some food stored in the back room that expired in 2007 and 2009 and was supposed to be refrigerated after opening. She was still using it even stored in a warm room. This explained why even though I may have just cleaned the fridge out I would sometimes find things so out of date I couldn't figure out how I missed it the last time. She won't let me throw anything away telling me she has done it before and its been fine. She often tells me she has a flu that may lasts two or three days . I asked my Dr why she gets the flu so often and he said they have no two or three day flues anymore. It's probably a mild case of food poisoning. He told me a lot of people think its the flu but when its that regular he is pretty sure it is mild food poisoning. I hadn't told him about the food she leaves out and eats if I can't get it thrown out first. She takes good cuts of meat out and makes a meal then walks over and throws it in the garbage telling me she did not like it. It kills my grocery budget.