My Best Friend Moved Away Last Week

I guess everyone moves eventually, but when my best friend Lily moved to another state last week, I was hit pretty hard. We were like sisters, well, closer than some actual sisters I know, and we did everything together. Since the day school started this year, she's been the only one who really understood me. Now that she’s gone, I don’t even want to hang out with anyone else because it feels too weird. Is there any way to get used to being without her? Am I just a total loser for not adjusting well?