What should I do about my imagination?

I'm almost 16 and ever sence I was a kid I had limitless imagination but all I could put it into was imaginary things and dragons. I have been told I have a great gift in writing, I have written hundreds of short stories as class assignments some being 10 pages long. I really don't know if I could go out for being a writer. I'm really good at it but sometimes I don't want to make a big deal of it. I'm very shy at getting a lot of attention so I'm really kinda scared hof how much attention this will bring to me. So far, I still get red in the face when it is said infront my class of 30 or so kids. Think anyone of you can give me some help if I should go on doing my stories or give up? And how long will my nervousness last?