I see this as you feel bad that the relationship is so poisonous between you, but don't know how to mend it. Even when you do something for your mum she turns it against you. Perhaps you need to stop trying so hard to please her?
Are you in her will, or in a position to make a profit from her in some way? Hey at least you are left holding the money!
As far as I'm aware, I would not benefit from her in any way shape or form as she has several thousand dollars in debt (mostly medical) and the only things of value she has will probably be sold for the debts.
I know I shouldn't try so hard to please her but I know she'll be dead before I'm 30. (She has Freidreich's Ataxia and she already has a rollator and will eventually need a wheelchair and than be bedbound before her heart or neuro system gives out on her completely) It's a weirdness.