I also don't think it sounds like schizophrenia/psychosis. My guess would be along the personality disorder lines, but this is the internet and we are not professionals, so who knows. But I think what matters is not the label, especially since she will never go to a pdoc to get a diagnosis/be treated, but how you cope with her behaviour.

I had a very emotionally abusive grandmother - at a guess I would say she had narcissistic personality disorder, but I don't know for sure. My parents finally cut her out of our lives when I was 11yo, but by that point a lot of damage had already been done. It took a lot of work on my self to get over the way that she treated me because I internalised it; thinking I was bad and that was why she was so mean to me. I don't regret cutting her out of my life at all: it was the only option for our psychological wellbeing. In fact, I wish that my parents had done it many years earlier, as trying to set healthy boundaries with her repeatedly failed.

But I realise how hard it is to do. Even now my father still gets abuse for cutting out his own mother (who spent his entire life telling him how she never wanted him and that she had wanted him to be born a girl!) - some random aunt who knows nothing about what my grandmother was really like just harassed him for not attending her funeral recently!! So it is difficult to go against social convention and lots of people won't be able to understand how you can/want to do that, but you need to do what's best for you. Whether that's limiting contact or cutting it off completely, only you will know for sure.

If you don't have good social supports irl, I suggest maybe seeing a therapist to help you make this decision, untangle yourself from your mother if that's what you decide, and to help you heal from the awful way that she's treated you.

Wishing you all the best

*Willow*