insecurities

i'm disappointed to my self because i thought i would be wise choosing my life decision and doing my school activities. But it comes out that i'm not really good in academic. i'm jealous to my classmates because they have a confidence and they understand easily our topic in each subjects. I always try to be positive that i can get a second chance to still be smart like others. But i'm having a second thought i'll not be good or smart like others. i look down to my self everytime i failed in every task.