aw A., what a sweet little soul you have been blessed with. i myself was one of those. i don't ever remember getting in trouble as a kid - my mom said i was always "so good", she never had to get onto me. but MY memories include her giving me a stern look and my insides dropping out in shame. i HATED her disapproval and would do anything to be the "good kid". i see some of my son in me. he's also very shy and sensitive sometimes. not always, but i see it there. his feelings get hurt easily. all i can say, because i don't have the magic answer either, is to love him to pieces. shower him with approval and affection and be a great mom to him. it's so easy when you have a sweet boy like ours. treasure him. what i tell my son, because he gets nervous/shy in lots of situations, is that yes, sometimes we get scared, but sometimes we have to do what scares us. that's what makes him a big brave boy. it's okay to be scared but we have to keep going anyway. it's not going to magically make it disappear, but i hope that it will teach him that it's okay to feel intimidated, and give him pride that he stepped into that room full of people anyway. it's so tough being the shy/sensitive one...!
(ps, i now what you mean about not being one of those coddling mothers - my son is physically the toughest kid i know! you should hear some of the KONK's i hear, and he just gets up and keeps going. even the bad ones, he will sit there a S., and i'll ask him, are you ok? he kind of shakes it off and takes stock, then he's like, "yeah, i'm all right." and just keeps going. then he'll have a goosegg on his head a few minutes later lol)