Not the first, not the last...only a speedbump on the way to tomorrow.
Want some advice?
Learn to fix your own messes.
Everyone makes mistakes; they're simply the chasms between your skill level and the challenges life throws your way. How efficiently can you recover? THAT is the question. That's the part that's up to you. Life deals the cards...but YOU play the hand.
Confidence on this playground comes from doing: living your errors, correcting them, learning from them, and moving on. If you're paying attention, eventually you will stop being nervous just because there's a test.