[nods] If it helps, I know how that feels.
My mom has severe mental problems and its a wonder I don't have far more severe ones. For lack of any other term, she really just doesn't get it and is mentally not capable of getting it: interacting with people at all. She will say the exact wrong thing all the time and she is absolutely incapable of understanding why people react badly to her. It's like the dog who jumps on everyone and wants to lick their faces while sniffing everything and "playfully biting," so far as it is concerned, the dog is just saying hello. It cannot comprehend why you don't want it jumping on you, while licking and sniffing every square inch of you and giving you little bites. Said dog is hurt that you don't want that and can't comprehend why you don't. She has told her boss to fuck off at his own wedding, told salesmen what they sell has no class in front of a very nice showroom full of people, called lots of women fat to their faces, called a bartender an unspeakable name for cutting off her booze and other things I can't even put in print. She will try to physically attack you if you mention a psychologist.
So I have recently been trying to have some relationship with my mother (and keep her from trying to go to that casino again before she loses any more money), and that consists of sitting there with her for some limited amount of time at her place watching whatever TV show she happens to have on while ignoring her complaining or smiling and nodding about it. She will often not even have TV on and will instead just start yelling at me while we I calmly sit down.
I have found a way to deal with this though. I take out a leather zip up binder and pretend to be taking god damn notes. In reality, my smartphone is streaming TV and she can't see it due to the binder. She truly doesn't know what's going on, because I don't think she realizes this technology exists. It's the only way I can sit through two hours of screaming abuse so that SOMEONE is there with my mom, because literally no other human being will voluntarily hang out with her due to said extreme social awkwardness/ total inappropriateness. It's both immensely sad and unimaginably infuriating. She's sick and I know that, but part of her sickness is being a completely caustic asshole to everyone, even and especially people trying to help her. 'The hell do you help someone who is intent on repaying your kindness with a figurative gun and insulting you as stupid for even trying? [shrugs]. If she ever figures out what a smartphone is, then it's all over.
Recently, after yet another sad hour day, I blew up at her again. I reach my limit about every 3 or 4 months. [shrugs] I dunno. I try.
Hang in there man, you'll figure out a way to deal eventually. (and so will I).