Well, it sucks, but you have to respect his decision. If he wanted to move on, then there's nothing you can do, as you can't just force someone to stay with you.
Just try to keep looking forwards, you might find someone who you get along with way better and who possibly has more time for you. Take the time to get over this relationship though, don't try to jump into a relationship so shortly after being in one, but that's a given I guess.
Anyways, take it easy, hope you can recover quickly! There's a lot of people in the world, and odds are that tons are compatible with you.