I'm approaching 21 in a few weeks and I've been making 6 figures since 19, I could have articles written about me but I choose to remain relatively quiet about my "success", millions of people use the things that I produce. My advice to you would be just do it, just do whatever it is you want. It's probably unique to each individual but I personally find that when someone tweets about my products or the things that I have produced it's the greatest feeling in the world, but when someone says "whoa you're 20 and you've done that?!" it's so hollow. Imagine your achievements being talked about because of your age? The internet is not discriminatory towards age, you can be 15 or 90 and achieve great things, why have them trivialized by an uncontrollable personal attribute.
As an aside I am also a poor programmer, although I can do everything I need to I am not a "rockstar" like a large portion of HNers would lead you to believe you need to be, but you don't, what matters is that you actually do stuff. Sit down, write code and maybe you'll achieve something great, but if you spend your time lamenting about how it's never going to happen then it never will.