When I go on courses, the first day I figure out who the problem people are (gum chewers seriously wreck my head) and position myself away from them. That often means coming in last to class or sitting up front to avoid a visual stimulant.
I think as you get older you are much more able to control your environment, whereas in school you’re just stuck there and that’s very stressful. If you need to get out of a stressed situation in college you should be able to do that until you feel able to cope. I’m always trying to manipulate the world around me to make it easier for me to cope with.
Do you do relaxation exercises? They can help a lot when you’re in a bad place 😉