Im already experiencing the downhill part. A player just left my match and it just canceled the game . Guess I should feel thankful it doesn't just allow the game to be 5v6.
I hope this comment gives you motivation as I was exactly in same position as you. I was going through same nervousness when I played my first ever comp match. I overcame my nerves and won the first match and ended up losing remaining 9 matches. Good luck!