Treat it like a job. What hours will you devote to grad school, and when will you clock out and live your life? Make friends OUTSIDE OF YOUR PROGRAM! Grad school can be all-encompassing if you let it. Friends from other parts of your life will help you maintain perspective. Keep/develop hobbies that aren't related to what you study. Grad school is part of your life. It isn't your life. Have fun and trust yourself. You belong there, and you have what it takes to knock it out of the park!