How to get rid of the mental block in snowboarding.?

Question

I'm 15 and have been snowboarding for 3 full season's and skiing since I was 2. Now that I am a full time rider, I feel like I should be getting better.. I compete, do okay but I feel like I should be keeping up with the tougher guys.. I feel as if i'm a decent rider, but for the past two years I have been trying to get a 360 down and cannot get it! I spin frontside. Can anyone help?