Does he like me or what ?

So there's this guy ive liked for a while now. He told me on fb that he liked me and I said I liked him back. Whenever were both online we always talk to each other but yesterday whenever he was on he would just say I gtg to me and leave. And today he was on facebook I said hey and he didn't respond ?? I don't get it, if he likes me dosent he wanna talk ?