I don't think I'm over her. Help?

So basically there was this girl and she was my first kiss. We hung out every weekend, it was great. I moved unexpectedly and we have no contact at all. I keep thinking I like girls at school but my head goes back to her, so I don’t really know. I get really sad thinking what could have been and feel wrong for leaving her. This may just be me venting but if anyone has any ideas about why this happens and why I can’t get over her, I would appreciate it. Thanks,
bboy