I REALLY thought he liked me. Some annoying girl made someone hook them up, and he said yes. Help?

I don’t want to talk about it too much, I mostly need support.
It’s not a fact that he liked me, but you know when everything contradicts each other? Alot of things he used to do gave signals that he liked me. Then all of a sudden he stopped. So not only does he ignore me, but he pretends I don’t exist.
Note: The girl is a bitch, and I’m not just saying that out of hate. I’m being serious. And what’s up with the shitload of makeup she wears? She’s also two years younger. So yes, you can imagine how annoying that is.