My mother always had "functional" paranoia (others stealing from her) with horrible narcissism. She is 87 now - still stubborn, strong as an ox, about 90 pounds, and mean. She wishes my children to suffer so I "get what I deserve" and at that point I tried to walk away. BUT, she needs help.
From what you wrote, you will not be able to help your mom out, doing anything of any kind. You are just leaving yourself open for upset, anger, heartache and frustration. Sometimes, Vernzog, we have to just throw in the towel and let whatever is going to happen, happen. Your mother sounds like a guard dog chained to the bumper of a car in a junk yard.
People who post on this site often recommend that you’ll have to wait until something happens to your mom before you can get her help. A fall, an illness or some other incident. It’s not pleasant to think of or plan for, but in this case, any attempts you make to help Mom will be pointless. You can’t reason with people like her so don’t even try.
what kind of help are you trying to offer? meals? bill paying? chores?
someone else will probably have some better advise.
maybe call your aging and adult services