This is so difficult to handle and have to say you sound like you’re handling it as well as possible. The parent child power dynamic plus complications of advanced ageing really do impact on how you deal with it.

I think you’re very wise at pulling back from committing to becoming a carer posh girl, being an unpaid carer is hard enough without this dynamic.

Hard though it is staying calm (I know that’s tough when she’s pushing your buttons) and asserting boundaries firmly as rechu says seems like your best shot. Limiting time with her seems also a good plan as is seeking support (as you are here) from others.

It’s so sad she doesn’t seem to appreciate you in the way many others might. She must be deeply unhappy, this behaviour is in no way a reflection of you or your worth. Really, calling someone a drama Queen when they are crying is very telling.