sir, i am a student of b.tech . when my heart rate become fast due to reasons (like,i have to present in an interview,i have to speak in front of crowd,at exam time,and when i fell that i am in sight of many people) then my body starts tremble(kampan).my hands does not work proper and tremble very fast so i can not do work properly. and i become depressed and in more tension. i am already taking BETACAP 40 for this but i am not satisfied. please solve my problem by telling me the reason of this and a proper medicine.