Let me ask you this: does your mother have any sort of medical insurance that might cover part-time nursing care? Are there any other family members who can help care for her? I understand that we feel compelled to help ailing parents, but you're getting locked into codie overdrive by dealing with such insanity.
To be perfectly honest with you, I dropped out of my parents lives. My mother spent the last few years of her life in an assisted care home. I hadn't spoken to her for many years. She basically died from heart disease, but she was mentally ill too. My father married my stepmother after he had a near-fatal stroke. She took care of him until he died.
It may sound heartless and cruel, but I cut my losses years ago. I felt no attachment to the two people who gave me life. Why should I? Neither one of them were capable of anything vaguely resembling love for their only child. Sad, but true ...