Best way to move on from someone you love?

[alien001]

This girl really felt different, I didn't want to fall in love but I thought we'd last. She ended up leaving me, even though she says this shouldn't be the end of us, but I don't think she'll come back. I mean why would she? I'm really pathetic and there's lots of other people that would be better for her.. I want to get over her but I can't get her off my mind. I'm always checking phone and get upset every time because she hasn't texted/called like she used to everyday. And I get so excited to maybe see her at school but she always looks away or goes in the other direction making me feel really worthless. How can I get over her when she's been the only thing on my mind for a really long time?