Yep, we are in the same boat. DS7 being pulled out for 4th grade math, says he doesn't fit it. He also hates being the youngest (since he skipped 1st grade). I told him all the kids in the class are different in one way or another. Someone is the the youngest, someone is the oldest, someone the tallest, the shortest, someone has blonde hair, black hair, curly or straight etc. Did it help? I have no idea.
I don't want him to feel different but the fact is that he is different. My heart goes out to all of our kids. I dk what the answer is. I just hope is gets easier and not harder as they get older.