Other people doing sports, how do you manage your time?

I (16F) play girls vb, but I am struggling with balancing my school/life balance. I play at a high level, so I have three hour practices every day, and compete in tournaments around the us. As I'm slowly starting to get into high school, where grades matter most, I am starting to let my free time slip through. I want to be a successful student, and balance that with my sport, but still have time to hang out with my friends. Any tips?