Accept that this unfortunate event will actually help you make a better and tougher person if you can rise above it. And frankly, if you cannot rise above this kind of incident, I don’t know what to say. This is an actual, real life issue you have to learn to deal with, not some PSAT problem. Realize that the way you overcome and accept this challenge is far more important than what happened to you. Face this as a challenge to accept and overcome and learn humility that this can happen to anyone. Bad things can happen to even the hardest working or most talented people. It’s called life.
Obviously, you are a very good test taker and had a lot of academic success so far in your life; but you NEED to laugh at this kind of event and move on.