Goodness, I think I've made things worse! This morning before school I was talking to him, and casually brought up that he was getting a report card on Thursday, and we would have to do something special for him if it was good. He burst into tears and told me he was afraid it wouldn't be good. (For the record, I have already spoken to his teacher - and she told me it was EXCELLENT). So I thought I would reassure him in case he does have a bad one in the future. I told him if he had a bad grade, we could work on bringing it up - but he wouldn't be in trouble for it. Then he became afraid that his teacher would give him bad grades for getting in trouble, because she was mad at him. (All year so far, he has gotten in trouble ONCE for talking in class when she was trying to teach - not a big deal at all).
In any case, I'm not sure I handled it well. My family has a history of anxiety disorders, and I wonder if I should get him evaluated for that sort of thing.