I hear you man, we're in the same boat. I'm 22 and getting ready for my seinor year of college football. Right now its 7pm friday night and everyones running around drunk, girls are all dolled up. People are on their way to the clubs and I'm cooking 3 chicken breasts and getting my workout gear on to hit the gym for a shoulder workout.
Sometimes I feel like i'm missing out on all the fun drunk times that make college so great, but if I went out tonight and got wasted I'd be pissed at myself in the morning.
I just keep myself focused on the fact that on saturday afternoons next fall all these kids will be in the stands watching me play because I was willing to sacrifice more than they were.