You cut them out of your life.
If someone is causing you grief or a hindrance to your mental health, it is perfectly reasonable to cut them out of your life.
You NEVER have to put up with toxic people.
Basically just sit them down and send them a long email explaining everything. Tell them you need to stay away from them for a while. Tell them exactly what they’re doing that is hurting you. Tell them what you’ve tried to do or when you’ve tried to tell them, and how their reactions aren’t helping.
Emphasize that it’s for your mental health that you need to be away from them, and even if it completely and entirely their fault, try to emphasize that the behavior is the real problem, not them as a person.
Despersonalizing the situation is important, as blatantly blaming them will just make them mad and not want to listen to you.
Ex:// “You’re being a dick because you’re a piece of shit.” doesn’t usually go over well.
Try: “Look, lately you’ve been doing [x], and it makes me feel like [y] because [z]. It’s not safe for me mentally to be around you right now until you [a], [b], or [c] to fix the problem.”
Something like that.
Make it clear what the problem is without it seeming like they as a person are just inherently bad. Attack the problem/behavior and explain why it isn’t working, why it’s harmful, and why you can’t put up with it.
Have you tried to talk to them about it before? If so, mention that. You tried to fix the problem by bringing it to their attention, but it didn’t work for whatever reason. Then let them know what needs to be done to fix it.
I hope this helped! ;o;
If you need to just cut them out of your life, that’s what you gotta do.