I'm looking down at myself

I always tell people that don't ever look down at yourself,but now i'm the one who are looking down at myself.I just feel like crying because i just made my family and English teacher disappointed on me.I told everyone that I will get A for my English but at the end,i over confident about it and i make a huge mistake that i shouldn't do.I'm just telling myself,why can't I just be a clever boy that makes everyone smile and happy?why?am I that stupid until i make everyone disappoint?I try to become one of the clever one but I can't.I'm not good in anything even sports.I'm just a useless person that can't do anything or maybe can be categorize as spoiled brat.I'm a sad person that don't care what gonna happen to myself but I don't want to see people around me to be sad,because they are my medication.When they starts to smile,i will smile too.Thats why I always make people laugh back or bring back their smile.When I do this,I don't want anything back.I guess thats is only what I'm good in,making people happy back or being a shoulder for people that need help.I help most of my friends when they need a shoulder,I'll be there for them.I'm just helping out.I know that I'm not a type of person that always pray to Allah.I know what I'm a guy that full of sin.I don't no why I'm like this.But I always hope that Allah can forgive me for what i did.hmmm.I worry that i won't be having a good result and i'm worry about making other look down on me for what I did.Last words,I still got 1 week of final exam,I hoping that i can do well in my building conc,building met and maths.hmm.all the best for me.