Everyone is good at something(s).
Wat ur good at is just not as obvious as some of that other stuff like sports.
For example, u r self reflective enough to write this thoughtful, philosophical, and dare I say even moving question on Yahoo Answers.
U say u "can't write like u thought u could," but u clearly CAN write. Ur definitely better at it than many ppl ur age. It may not feel special to u because u already have that talent, but trust me, no 1 ever truly appreciates the talent they have.
Hang in there kiddo.