Well, nobody's expecting you to be Charles Dickens or Sir Arthur Conan Doyle or Stephen King...just do your best. Everybody improves over time, especially as we sample the works of others. That's why this is the perfect training ground...
I mean, I've been writing since seven, but I never wrote a full-length 170-something page novel manuscript until 12th grade (and I'm still working on what will be my second)! So no worries. Everybody moves at their own pace to develop writing prowess of which they can be proud.
Just...find your center, young grasshopper.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)