Hi,
Circumstantial, I can only say good luck in your game design interests.
The reason I say interest is because you will not be able to expect to get into game design making good money. Plus it is a highly competitive field, I mean who wouldn't want to get paid making games like Starcraft 2, or SINS.
The trick to get into game design is to get involved with a mod for one of your favorite games. This will give you valuable experience and a resume to show to development companies.
You must also choose what do you want to focus on, the programming aspect, or the art aspect.
This can affect which college you go to in the future, like the Academy of Art, or Gnomon Digital Art School. Both are very pricey, but will get you up and running with a portfolio, and familiarity with all the industry standard software like 3DSMAX, MAIA, PHOTOSHOP.
If programming is your pick, there are more colleges to pick from that offer this course, even some with a focus on game design and theory. This sounds more like a pick for you since you don't seem to be an artist.
One of the original classics Duke Nukem's engine (powers the graphics) was written by a smart kid like you, Ken Silverman, read about him from his own site here: http://advsys.net/ken/
In the mean time while in high school with your bills paid, a warm bed to sleep in , and no family to worry about, you can learn all about what I mentioned above for free!
Microsoft started an XNA Game Design club of sorts that offers tutorials and even express versions of Visual Studio (C, C#, programming language)
XNA Creators Club
http://creators.xna.com/en-US/
Nick Gravelin has excellent tutorials (Though someone outdated)
http://nickgravelyn.com/archive/
XNA Resources (Tutorials, etc.)
http://www.xnaresources.com
Good Luck! Maybe you can write the next great 4x Classic!