Oh, Anna, breathe (ithelpsxD). It'll work it's way out. If the guy can't keep a stable relationship with this girl he's "Dating", do you want to be on and off as well? I think the way guys treat girls and their girlfriends, tell a lot about them. If they aren't nice to them, would they be nice to you? Idk if this is helping, it's my sensible side.
Now for my totally sensitive side! Woot!
That's happened to me too Anna. A boy I used to like was super cocky, and drove me insane half the time. The other half he was still annoying, but I loved him anyways (wedidn'tgoout). Then I fell, fast. We danced at the next dance, all the time. I had to tell him that I had feelings for him. So I did. Then BAM! He didn't like me. Who knew guys could be so confusing? Instead he went for my best friend instead, and now he can't even look me in the eyes.
That might've shown you that we will survive either way, I wish you the bestest.