Welcome. You've found a safe place to vent. I have no advice to offer except to continue doing what you think is right for YOU.
I'm lucky that when my mother lived with us, we rotated with two of my sibs so that we only had to deal with her 3 months at a time. This was for my DH's sanity. She really got on his nerves.
I hope things get better for you soon. Check in when you can and let us know how you are coping.