I was the nerdy kid in school, glasses, buck teeth, bad skin, poor. You name it. I got picked on in school until freshman year and my dad always told me to never start a fight but make dang sure I finished it. Problem was that made me too scared to throw a punch lest my dad hear I threw the first one. One day I got fed up, threw a heckuva haymaker as the first and knocked the kid flat on his ass out cold. Didnt have to fight for another 3 years, against a much larger kid my junior year in high school. Threw the first one on that one too. Figures I knew it was coming so I might as well get the first one in. Kid stayed on his feet, but I blacked out from adrenaline and wiped the kids tail for 10 minutes straight until people felt sorry or him enough to pull me of him. I do t remember anything beyond the first punch. He was the school bully, and in a school of over 1000, it didn't take long after that for him to realize he wasn't as big as he thought.
Let your kid handle it and tell him it's ok for him to handle it. Hats the best thin for you to so at this point