I am ten years older and just starting out. I was laughed at when I was 16 when I announced that all I wanted to do was fly for a living. The mistake I made was taking notice of these tossers and thinking my dream really was just that. Don't let the bas%$&ds grind you down. I did and I regret it. You've got age on your side, stay focussed and turn the dream into reality.
Of course, getting a class 1 medical pass before you embark on all this goes without saying!
Best of luck
Nigel