You might want to have someone stand behind you when you shoot, they might be able to tell you where you missed which might help you out.
The best piece of advice I can give you is to keep your head down, keep shooting, and don't think about misses.
Thinking to much is a real killer. I remember shooting in a tournament and all I needed was a 24 in the last round to win top shooter. I missed number 23 on a easy straight away hit number 24 on another straight away but couldn't stop thinking about that miss and ended up missing number 25. So I ened up with a tie (to a girl). She had shot a 25 in the earlier rounds and my best round was a 24 so she won top shooter. That was a hard pill for a 15 year old kid to swallow. But after that I never thought about a miss until I was done. Then I would talk to my dad about it.