It sounds like you did try to ask both sides to call the other to make peace. That’s all you can do. Now, you are just being badgered. You also have a right to be hurt at how your mother criticizes you. Her children do not care about her because she’s MEAN.

I’d distance myself and keep a careful balance. You don’t need to go out with fever because you are being bullied into it. Boundaries! Enforcing them and being respected is going to be nearly impossible with toxic people, but stay firm to yourself because you are the most important person to you.