how do you get over your ex?

So my ex broke up with me on New Year's <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>, I know right what a dick! But anyway I don't miss him because I knew that it had to end but I just miss having someone. I often go out partying because I'm 17 and I always used to come back and sleep and cuddle with him at the end of the night. But now I can't:( it was just nice knowing that there was someone there ya know. Anyway how do I get over this and stop thinking about him and what if things were different?