After giving more thought to the appropriate words to give, I want to lay them out here. I am calling it:
Here you are and how far you have come. There is fear in your eyes and worry in your heart, but it is all misplaced. Let me explain.
If you are worried today, it is probably true that you have been worried all semester. That worry, so long as it is measured and not disproportionate, has served you well. It has pushed you to master content to the best of your ability given the constraints of time, life, and your effectiveness as a student.
If this is you, then you need not fear today. Take your fear and transform it into confidence. You need not worry either. Worry is for yesterday. On the day of the exam, take your worry and transpose it to alertness and focus. Dark chocolate will help you to do this.
If the above does not describe you, and you do indeed have what to fear because you are indeed under-prepared, much of the same applies. You are, and probably have been for some time, in what may be referred to as 'damage control mode'. It is a hard place to function for extended periods of time. The good news is it will be over soon, as next semester is a new one, and you are free to transform from the start, and alter your functioning such that the patterns that did not serve you this semester are replaced by patterns that do.
I want to tell you about one student I had some years ago. She may be unaware of this to this day, but she actually smiles from ear to ear while taking exams. I never told her about it, because I did not want her to be self-conscious about it. From my point of view, I had to restrain myself from laughing during examinations. There were forty students sitting in front of me; thirty-nine of them looked mildly panicked, and one is simply beaming. In another context, this could be the setup to an exceptional horror film.
I am not suggesting that you should smile while writing exams. What I am suggesting is that the confidence you have rightfully earned should allow you to smile on the inside while you maintain your serious exterior.
Be alert. Remain focused. Hundreds of hours have been invested on your part - your worry is now over. It is actually possible to enjoy the moment, and celebrate how far you have come.