I am so close to Varsity badminton. What should I do?

I am challenging (hopefully) my friend this friday for out school badminton for the varsity singles spot. And everytime I play him, I lose the same way I always lose. I do so well until around 12 points (21 to win the game) and after I get about 12 pts, the other person starts catching up and eventually beats me by around 5-6 pts..Please help! I really want to make varsity!