i desperately want him back please help me?

My boyfriend said he loved me we were together for two years and then out of the blue he says he just wants to be friends. A few days prior to that he said he was never going to break up with me and he wanted us to work out. then he breaks up saying that we are too young and he wants to see other people. idk what to do. i just want him back. he always treats me like shit but i take it all in cuz i love him