Brandon, I am sorry to say that height is not controllable.
I bet, though, you can find claims of "heightening" methods on the net but don't fall for any of them. None of them can be medically realistic.
Keep hope, though. At only 15 years of age, you are likely not done growing in height....and it is not completely uncommon for one to grow a couple, few or even several inches in a year's time.
...now if you start shrinking,
then you can worry
