sad tonight

I'm sad tonight. I read some news about the guy I still fancy (I f******cking hate myself for it)and my mood dropped instantly. I'm sitting here, thinking of nothing, feeling nothing. I don't know why I'm still so upset and why I let myself being hurt.
I still dream about him regularly, and then I wake up and feel like shit, because I thought it was true and he really fancied me. But he doesn't and it breaks my heart being treated like this.