Sounds like you were the top dog and you're probably afraid to be a smaller fish in a big pond now.
Majority of my friends couldn't wait to get out by senior year, even amongst the "popular crowd" who seem to embrace and get the most out of high school, you just get tired and want to move on. It's normal to miss it, just so long as you're not afraid to "go out into the world". It's understandable to be nostalgic of the good times you had, because life really won't get any simpler than in high school, but there's a lot more out there.
High school was fun. Between parties, football/basketball games, pep rallies, girls, joking around with friends, etc. But you still had to go home to your parents house every night. It was a lot harder to drink and partake in other
activities. You had to deal with frustrating teachers and you were surrounded by the same kids for 4 years in a row. It had it's perks, but college is much better. Being on your own, meeting new people, learning new ideas and philosophies, taking classes
you want to take, broadening your horizons and options in ways most high schools can't offer.