Help -- I think I've gotten worse at singing

Last year I did so so so good in hs choir. I'm an Alt 2 and I got 3rd place in my district like 5 months ago and went to all-state. But this year, everything turned upside down. My teacher said that it wasn't my best and that I could have done better. But I tried, I really did.

I dont know what to do. Maybe it was just the song? Or just the nerves? I probably got around 10th in district but I can only get 4th or above to go to all-state. It's my senior year so i rlly rlly want to go.

What should I do?