Well you can't change the past...I don't have a problem with my past. While not squeaky clean, I did get my feet wet with both the worst and the best society has to offer.
First and foremost, you need a goal....some goal, any goal. I don't think it really matters what you are interested in, and if you are even any good at it, as long as you have a goal and moving towards it....and persistance, persaverance (sp?), and discipline is all you need.
My short term goal is to teach at this community college...so now, in class, I try to think of how the teachers prepare for class. Most of my professors walk in with nothing but a marker, but they have been doing it for a long while.
I don't have a long term goal of what I want my life to be like....I don't think I can accurately predict 5 years out, but I can predict 1 year or so out with good certainty....thus controlling it. And I am fine with that....it's only when I start to worry about a longer time horizon, do I get depressed.