My friend has changed ever since highschool. Why?

Ever since he went with hes new group of friends on the basketball team hes been acting wierd. He listens to loud rap music.. Hes ALWAYS showing off and being mean to me. When he goes to hang out at KFC he acts like he doesnt know me. He spends all hes money on earings, necklaces, drugs. I told him hes changing then he said " Shut the f*ck up trick yous a sucka" Even at lunch he wont share stuff with me like he used to not even hes kool-aid and watermelon.. What do I do help?? I want my friend back from this new "crew" hes with!!!