Tot Has Penile Pain During Urination, Itching On Penis. What Could Be Wrong?

My 2 year old has been having weird things going on with his penis , for about 2 weeks now when he starts to pee he bends down and holds it like it hurts. I thought it was just because we started potty training. He also likes to pee in the bath, like under the water he ll ask for a bath just because he has to pee. But last night he woke up hitting his diaper and crying, so i took it off so he could show me what was wrong, he started itching his penis and grabbing his balls hard, I massaged some of his exzema cream on it and it seemed to help but every couple hours he was doing it again, we ve had no sleep at all tonight. Whats wrong??