I also experience this

Make it known to your teachers and see if you can get an accommodation written up stating if a situation like this happens you can leave the room immediately no questions asked until you calm down. My son and I experienced domestic violence and we are both the same way.

This isn't a perfect solution, but are you able to bring a comfort object to help ease anxiety in the event of a fight? Sometimes I carry a worry stone in my pocket or wear a little clip on stuffed animal on my belt loop to squeeze if I get anxious in public. A friend of mine used to carry a tiny plastic duck in her pocket to her retail job as a little friend. Or it could be a necklace with a comforting charm, even something like a crystal or religious symbol if those things comfort you, anything small that can be used as a little source of strength or a grounding mechanism. And another idea would be a breathing technique, I used to get panic attacks in class and they helped sometimes. There's a few different ones on google that you could practice in advance and see if any work well for you, but my favorite was the 4-7-8 technique (deep breath in through the nose for 4 seconds, hold for 7, then out through the mouth for 8 seconds)