What am I really good in?

I...
My mind goes strange these few days.
Recent day, I get a poor result.
I think am I really that bad in that subject?
Or I am the only one who is the worst in class?
Sadness takes charge of my thoughts.
Hurt feeling scratching my soul.
The only feeling I have is,
Empty,
Disappointed,
As a street rats.
...
.....
I did a script which pretty important for my grade.
I ask my friend give me some comments.
If possible, I'll welcome if there are any advices or suggestions.
I can't get the "comment" that provided by my dear friend.
I spend time to do it; use lots of energy to check, share and edit it; double, triple and more time to re-do, re-write, think it again and again.
What I get?
Pieces of rubbish!
What I think I am good in is no longer there.
Everything I did, I try, I struggle are waste, useless, helpless!
...
....
Nut people doing nasty things!
Brainless people wasting anything!