I had a really hard time at a large University where you were elbow to elbow with over 125 people in the room who were coughing, turning pages, dropping books, etc. And it would all sound amplified if I was anxious, racing thoughts, moody, etc. I would loose my train of thought and have to start problems over. I got two D's and two F's that semester. Took a leave of absence the next semester. I don't have any suggestions for you. (I should have worn ear plugs come to think of it.)