I can't take this anymore!?

Ever since i found out i got something wrong in my math test i have been stressing over it. It is not the fact that it was only one wrong ( or one that i know of) its because my first answer was right and then i changed it to a wrong answer.

It seems shallow i know, but im aiiming for the highest award this year.

How can i just get over it? I hate being so competitive, it is so stressful.

How can i get over it? i know im not a really shallow person, just when it comes to test and yeh.

:s