How to get over this??? Feel like crap?

So ever since 2007 I knew I wanted to go to the Citadel (a military college). I was suppose to start as a freshmen there in the summer of 08 after high school, but there was a mix up and I had to wait an extra year. After waiting a full year, which seemed to have taken for ever I was finally there, the process took forever! All the paperwork and financial aid and getting into good shape. But after being there for 3 days in the summer of 2010, I quit. I still have know idea why I quit, but everyday I regret it and I find myself dreaming about it 3-4 times a week. Also during the day i'll drift of and daydream about it for a long time.. I still feel like **** for quiting and don't know how to start feeling good or forget about quitting.