Teen Growth! - can worrying about not growing actually stop you from growing?

I am in my very early teens and about 5'6 (1.68cm). I have never considered myself short in any way, however lately my so called "friends" have bugged me a lot about my height. So therefore I have become very interested in this whole growing thing and I am really looking for some good answers. When do you stop growing? Can stress affect your growth? At what age do you reach full height? What can one do to become taller? I know for a fact that I have not stopped growing yet, and I eat a very balanced diet and I do athletics 4 times a week so my body is in great shape!. Thank you in advance for the answers! I really appreciate your help.. =)