How do you cope?

It used to be so easy, I spent most of my teenage years alone, and I was relatively happy. Everything turned around my senior year. I made friends, they got me out of my shell and then suddenly it was like I actually had a life. And then I moved away, and I’m all alone again. But it’s so much worse — because now I know what it feels like to actually have people. How do I learn to cope with this?