Last year as I was in the plane and seconds away from doing my first jump in 6 months, I realized that I was completely frightened. I kept thinking, ug..what the hell am I doing??? My hands were shaking and my heart was pounding like crazy. I looked at my instructor and said, "I'm scared." I will never forget what he said to me: "You should always be a little bit scared. If you ever get to a point where you are 0% nervous, you shouldn't be in the sport."
Being a little bit scared keeps you on your toes and that is a good thing. Being "scared shitless" scared is scary in itself. The fear breeds more fear (for me, anyway). When I get to that point, I always think of the euphoric feeling I get the second I jump out of the plane. There's nothing like it in the world, and that always helps to calm my nerves.