Don't worry too much!!
Honda450R,
You are still very young. I know it seems bad right now, but your body is going though so many changes that you have no idea what will work for you. You could find something that makes the changes you want, but then your body chemistry changes next year and you have to do something else.
I know this is NOT what you wanted to hear, but you are doing everything you can in the fitness department. I ran X-C, too. Great sport. You are active, healthy, and strong. That is fantastic!! You do need to eat more fruits and vegetables, but so do all teenagers. Junk food will definitely hurt you, so try to get most of your nutrition from good food instead of from supplements. Stay away from most of them at this stage. Small, frequement meals will help keep your body from hurting itself.
To be 6 foot tall at 14 and taller than most boys is hard. Your body will need a few years to catch up with all the growth. Please be patient.
If you are really concerned, go to your family doctor and see what he says. But there is nothing wrong with you! You are just young and need some more time to let your body catch up. When you are a junior or a senior, you might be able to think about fat loss then but talk with your doctor.
In the meantime, best to you. Enjoy your youth -- it goes faster than you can ever imagine.