To add to that.... small classes are better generally. However, there is always more pressure because you can't 'disappear' in a small class the same way that you can in a lecture so it can feel more invasive and pressurising. Larger lectures are better for pressure... you can slip in if you're late! And there is little/no demand to participate, lectures you just sit back and listen- though I don't like lots of people, or a lot of noise.

My personal ideal situation would be lots of smallish lectures.

Something else I thought of.... I now have to have one on one sessions witha supervisor for my dissertation. This is really challenging to me, I don't like being in a room with a closed door with a man, it is effort with my therapist as it is let alone a lecturer who isn't necessarily trained to deal with that issue, or doesn't know about it. The pressure of being one on one has had me more anxious, and my supervisor has noticed it. And like you, I become more reactive.... which was embarrassing last time because he now thinks I'm an angry person and I'm not!

PS. I'm 22. And you mentioned dorm rooms... in the UK most universities have houses/flats/ halls where you have your own room. If i had to share a room with someone, there is no way I would have considered going to university!

Good on you for managing it!