How to stop son from obsessing over his size compared to others in the locker room?

I didn't have custody of my son until he was 6. He was tiny but I was told his poor growth was due to malnutrition. He was tested for growth hormone issues recently and discovered that he is deficient. This also means delayed puberty. He's 14 years old and is a freshman in high school.He does swimming and dresses out with the other boys. He has started to notice how far behind he really is in the downstairs region. None of the boy's pick on him but he can see that they are bigger than him. He has since decided he no longer wants to swim and has switched underwear styles so changing in gym doesn't expose his size as much. He used to wear briefs but switched to boxers. He has sensory issues and hates the way they feel but he doesn't want anyone to notice how small he is. He also has an almost 13 year old brother. They share a room and change together. The 13 year old is further along and the 14 year old doesn't want to change around his brother anymore. He freaks out so much about this and I caught him search for ways to stimulate growth. I want to make sure he doesn't do anything dangerous that could permanently damage him.What can I do to help as a single mom? via /r/Parenting https://ift.tt/2RSl4I1