The judges only see five minutes. You’re the only one who knows what the other thousand hours were for.

Any judgement is made on a sample, and a small one. Five minutes cannot hold the months behind it, so a verdict is about those five minutes and not about the worth of the work or of you. A good score does not prove the hours were well spent, and a bad one does not erase them.

After the result, do your own assessment separately from theirs. Ask what the hours gave you, and what you would change about the preparation rather than the performance. Keep that answer, because it is the only one with the full picture.