BTDT. My ds9 has and still sometimes does get very very worried if he thinks he's done something wrong. We were at a cub scout meeting the other day and I usually let the boys make paper airplanes while I'm talking to keep their busy hands busy...he threw his into a basketball net and came over to tell me. I explained a couple times I couldn't get it and not to worry about it, it was too high up. Finally after his asking again, I said, 'well, they're not going to finger print it! if you're really worried, you can make another and write an apology note on it and send it up there...', hoping to make him laugh. Partly because I was trying to continue the meeting, I didn't notice he was actually distressed.
One of the dads there did, however, and he just gently told ds he would try to get it, and to just try to participate in the meeting. I stopped what I was doing and looked at ds, his eyes were just saucers ~ he was really worried about getting into BIG TROUBLE. Sigh.

Similar note on social behavior except that ds himself felt isolated so we knew there was a definite change needed there.

Our approach after some assessment from a neuropsych was multi-pronged...social skills training course, helped both with finding better ways to interact, ways to back out of a situation that was going 'off course', and to see that there were other kids out there who sometimes didn't click with others. All the adults who speak with him are very impressed and enjoy actual conversations with him, but getting along with other kids was a puzzle.
Further, we had a few counseling sessions for him on anxiety; one pressure area is school, one is bedtime. Bedtime has gotten a lot better; my dh was a night shift guy, but has since changed that and it has really helped ds.
School anxiety is still sort of strange to me since he usually does A work; it is less about assignments than 'fairness' in some situations, getting in trouble on the bus because other people are misbehaving, he hates be lumped with others for behavior, good or bad. He wants to earn any praise legitimately.
Anxiety is less and less a problem as he learns the rules of the road, and it has also been a matter just getting older. Good luck to you and your ds!