BIGGER! I NEED BIGGER!?

I'm currently 17, can grow some peach fuzz on my chin and over my mouth (dirty sanchez mustache). I guess puberty hit later but i grew from 5'4-6'0 in 2 years or so, but have grown little to none in the last year. BUT THATS NOT THE PROBLEM! I have a 7.5-8inch , but I'm wondering if it will continue growing, because i have some genetic expectations on one side of the family to live up too (not sure how small other side is but thinks its average). I MIGHT be done growing height wise but would that end for mister genitalia's growth? I'm also in an awkward lanky stage (i guess you can call it) and wondering if its when i fill out and gain some weight, if that would effect size!