Can I do this?

Though I should be on top of the world, I'm kind of nervous. I took my last final in Advanced Human Physiology yesterday. I've made an A in all of my classes. So I should be jumping for joy, right? A 4.0 GPA for the semester is awesome. What is making me nervous is that the nursing students in the year ahead of me had four students flunk out just this semester. Since there are only 20 students in the class, that is a huge number of people. These are students who had to compete just as hard as I did, and made really good grades on their prereqs. I know if I were a patient, I would only want the nurse who really had an excellent grasp of the job, and that starts in nursing school, but I'm worried I won't be able to keep up. School has always been pretty easy for me, and I haven't had to work too hard, so do I hope and pray I have the dicipline and study skills to be able to do a really good job. I've wanted to be a nurse forever, and we spent four years getting our financial affairs in order so that we could live on one income in order for me to be able to attend school full time, not to mention I'll never be able to recoup an Outside Sales Rep salary on what I'll earn as a nurse, so I've just can't allow myself to consider not doing the best that I can.