My ex boyfriend

Ok, well me and my ex boyfriend were really good friends wayy before we ever started dating. He sent me a friends request on myspace after him and his girlfriend broke up. We started talking on there then we started talking on the phone. We would stay up all night on the phone and never run out of things to talk about. (this was before we dated). We have been talking for almost a year and a few weeks ago he decides to tell me he likes me and always has. He didnt think I liked him the same way. But the truth is I do and always have also. So we got that settled and started dating. Well now he sent me a msg and told me it is just not working out he didnt like me the way I liked him it is over no explanation or nothing. I replyed to his msg but he never replied back. He is now going out with the ex girlfriend that he dated before me and him started talking again. What do I do. How can I get over it cause I really loved him and still do. And why did he do me this way? Help!!!