And if you are as big as you say you are, then why the crap were you looking at taking steroids at such a young age. You are a monster sized kid! No need for that crap dude.
You are young and very built, you don't need to be looking at hyper dosing anything. Get more particular and disciplined about your diet, and take a good look at your training routines. That's the bread and butter anyways, and will make all the difference.