I don't know if your mother is a threat to you, but I can easily see why you don't trust her. You are an adult now, you have WAY more control over what happens to you than you did as a child. Way more choices are available to you.
It seems like I remember you saying something recently about your thyroid medication, but I'm not sure. It IS possible for thyroid levels/medication to affect your emotions. Maybe you should get that checked out, just to be sure it's not contributing to the problems.
Even so, you're in a difficult and stressful situation. You had a difficult childhood too, and are dealing with the effects of that. Handling your emotions, even HAVING emotions, is part of that package, so that maybe the problem too, or part of it.
I have had some issues with my own family. My T keeps saying, "I wish you would think of these people as just being 'interesting'". I've been trying to do that, and it helps. Rather than letting myself get sucked in to all the drama, I try to take a step back, disconnect the present situation from the messy past, and deal with them like I would if they were just some random person on the street. It DOES help. It helps me anyway. It doesn't change the craziness or the issues, but it changes how they effect me and my ability to deal with them.