Please help me i can just say help me...............?

ok i am studding in class 12 maths science group . i am a bright student from my childhood every one say that and i know that too. but the problem starts now when i stepped up in 11 class after going to coaching i found my self less brighter then other and with a great attitude i decided to work harder and did it but the problem is that i am afraid to compete with them whenever my sir gives us a question to solve i feel afraid and hopeless to solve it and i finely couldn't do that .my teacher is impressed with my Performance in class 11 but i am not satisfied because i no that i could do better and i can be the topper of my class but just because of my fear i am not able to do any thing and now i am thinking that how can i compete in all india level when i should work harder because i have much time.please help me to overcome this fear and to be that girl who was full of confidence.