Knowing that you care too much about the result, I am quite worried. Actually, it is no use being upset despite the importance of the result. There are some effective ways to calm down.
Above all, keeping reminding yourself to stay in peace is the most helpful. Besides, it will help you to relax if you spare some time for recreational activities like sports. Finally, talk to your parents and friends, who are always ready to comfort you.
As is said by Steve Jobs, “the journey is the reward.” I am sure you will get through this situation.