she is really mean and screams at me and her son, accuses us of stealing from her, of wanting her in a nursing home, and even accused me of attacking her (this after she has attacked me 3 times - once in front of a nurse. I know it isn't true, but I am very tired of spending 20 hours a week over there helping her and having her turn on me. there is no one else to help her... literally. No one.
And is there such a thing as the dementia patient abusing the caretaker?
I'm curious why you are spending 20 hours a week with your "ex MIL" -- do you mean you are divorced from her son? If there is no one else to help her, couldn't there be hired caregivers?