My mother was very unstable, delusional, freaked out screaming for hours on a day to day basis, dwelled on the past, accused people of things that clearly have nothing to do with reality. She wasn't someone you could talk to about her self about how she is, or how other people arn't as she say, or else it would make things worse. I don't know but your mother sounds like she could be similar? This might sound mean, but you should describe her more, I want to see if there is anyone else like her.
Anyways I eventually just ignored (in general) her for a few years then left and moved to another state with my grandma. I have not talked to her since, she just isn't someone you want to deal with. If I talked to her on the phone she would not make any sence.
Thats my only advice, if you can't help her, be passive around her, then get the fuct away. Sorry for the language. Complain in a post if you want.
Also with what the other poster said, it may look like you are being rude or hypocritical (ha I am being rude too for not talking to my mom) if you say someone else is mentally ill when you your self are not neurotypical, but, your AS does not even belong in the same category. AS is a neurotype, then a mental illness would come down next in another category if it we laid out in some sort of tree.