My 14yr ds had a fight with friend and changed friend groups. Since then he has picked up kickboxing, he's been going to the school gym practically everyday and acts a lot more aggressive. He now has a girlfriend and goes to her house a lot, at first I didn't think they've had sex but yesterday found condoms in his room. He. An be quite scary when he's angry as he's 6ft1 and has become a bit more bulky and doesn't know his own strength. I don't know what to do please help.