How can i be more confident in myself when i play in tournaments?

I'm a junior in high school. I'm a very good golfer. I've played for around 10 years now and I love the game. When i play by myself, or get paired up with people i do not know, i shoot very good. I love making people go wow can that kid hit the ball and because i love to impress people, I always end up shooting around par or just a little above it. When i practice with my team or play in meets with other high school kids, i tend to never shoot as good as when i play by myself. No, I do not cheat when i am by myself either. I feel like i lack confidence when im playing with people my age who are just as good or are better than me. I'm never "feeling it" when i play at practice or in a meet. It's almost as if i dont want to even be there. I just do not have the right mind set for some reason and i think a lot of it can be attributed to confidence issues. How can i be more confident when i play competitive golf? I'm #4 on my team right now which is good because my team is very good and goes to state every year, but if i dont start playing better in the meets, i could get dropped to #5 or have to sit for a few meets. Please help me with the confidence issue, i have a ton of talent, and i have yet to tap that talent during the golf season. Any advice would be great