Why is leaving so hard?

So I went to Lubbock this weekend, just got back about 30 minutes ago. I don't think I can go back again. Being with Patrick again was wonderful. It was like we never broke up. We went party hopping Friday night. All the parties were pretty mediocre but we were hanging out again. I had fun; it was good seeing everybody again, and I know for certain that moving back to OKC was the best thing for me to do. But that's not why I can't go back. I need to move on with my life. Saying goodbye again would be too hard. When he opened the door and I saw him again everything came back. Everything I felt for him came rushing back. I thought I had gotten over him. But...... My only stop on the drive home was on the side of the road so I could cry. I can't do that to myself again.

Good night and
Goodbye!