My Son! Help!

Hello,

my son is 14 years old going on 15. He hasnt shown any signs of puberty, he is 4"10 and in the 9th grade. He weights about 90-95 lbs. He often looks pale with blue shadows under his eyes during the day. I wonder if hes not getting proper nutrition which is delaying puberty. He feels insecure about himself and has very low self esteem. I worry about him sometimes. He finds it hard watching all of his friends grow and mature while he is left behind. This is what makes him stressed. He has no underarm hair or facial hair and he says his penis is still very small with no pubic hair which is very embarresing. He hates changing in gym because he has no underarm hair and some peope make fun of him. Please give me tips or advice or something!!!!