WOW! I'm jelous, I really want to dunk before I'm 18 (I'm 17, turn 18 in october). The closest I've got to was pushing the ball in the rim then touching it, not exactly dunking. I know what you mean by not having access to a gym. It's annoying, well for me it really is because I've got access to a gym (at school) but its so dusty, if I try I will slip and kill myself

And I'm 6' 1" with 29" vert, maybe 30" but still cant dunk
Your success story has inspired me to keep training! (currently doing vert bible novice plyos

)