Mystery

Ok.The results for 2 subjects among 5 in the finals have been annouced few days ago,and I got a B and B- for these 2 subjects.
My thought at the moment was like:hmm,ok..It's still ok although I aimed for A's..

But as I past through the day,I found out a lot people have the same results with me,or even better than me!!As i know more,I feel more and more inbalance.But,I'm trying my best to control myself.
Everythings is going fine and smoothly for few days,until today,before class started.Once i stepped into the class,everyone were discussing and holding stack of papers.Few minutes later,found out that those papers was our marked assignment.
Well,high expectation always turn out low results.My marks for assignments,is so less compared to others!!How am I going to score well with this assignment marks???My dream's gone...
What made me more imbalance was,my marks were even lower than those finish their assignment last minutes!!!And the thing is,I really do put 100%time and effort in my assignment,but I got a bad results..
Why?Can some one tell me why?
I really put a lot of time and effort for every assignment!
I really put a lot of time and effort in preparing my finals!
I even studied the lecture notes,text book!
I sleep early and have enough sleep before finals!
Why?
Why my results is almost the same with those who din't study?
Why can't I get a better results from all the effort and time I sacrifice?
Do I really need to put so much effort and time into my study start from this sem?Since even I sacrifice everything,I still get the same results like others who din't really prepare!
What should I do?
Oh gosh,I feel so helpless.........