How about I want nothing to do with my mother anymore?
Why would you want nothing to do with your mother?
I am tired of her suffering but I don't want her to die.
If your parent is toxic you should talk to them to try and help. If you cannot take it you should both go to counseling together and work through the problems.
I am tired of trying to help her.
It's hard to take care of parents when they are suffering. You must figure it out and make the best of the situation, or you will suffer alongside her. I lost my mother, and I'd rather be in your shoes than live without her.