"what if i'm not as good as i think i am?"
"what if i really cannot make it...?"
All i can say is that you gotta try. you gotta just try hard and wait. and if you know that you did your best, you just gotta patiently wait for that moment to come. all those years of hard work will NOT go to waste.
Believe in me. But more importantly,
BELIEVE IN YOURSELF.