You’re probably right that your paralysis has something to do with your history. As a child, you were helpless to get out of the situation. You learned then that the way to prevent further hurt was to essentially freeze. It was a survival technique that worked at least some of the time. You never learned how to be effectively assertive because it was pointless to even try with your parents.
Lessons learned in childhood are very powerful. In our early years, we put down a template for how people operate and what we need to do to get along. We then carry that template into every other relationship. I suspect that you generally avoid being around such difficult people. That works as long as you can get away. But, as you are finding, when you are stuck in the situation, your old survival pattern comes back. The problem is that it doesn’t work in your adult life.
This is exactly the kind of pattern that therapy can resolve. Therapy will help you separate past from present and learn new ways to take care of yourself. Your therapist will help you practice handling these situations during sessions and will give you support while you try them out in your life. You will probably also need to do some work healing the hurt child you carry within so that angry people don’t immediately send you running (figuratively) for cover.
You’ve carried the hurt long enough. Please follow through. Ask your doctor or someone you trust for the names of therapists in your area who have a good reputation. I always suggest that people give themselves permission to interview a few therapists before settling on who to work with. The most important variable for whether therapy will be effective is how comfortable you feel with the therapist.
I wish you well.