Well first thing I noticed going through the list of drivers out there in big motor sports championships is that their all european, so you first step is a european birth certificate.
Then most of them started racing at around 13 on karting tracks, your not 13 are you, if not you best get started since they spent nearly 5 years out there karting. By the time any of them started in cars they already had plenty of experience in racing, not many of them mention PS experience.
Then after all that you best start would be with the golf race series here in SA but you would also need nearly R2mil just to get your car ready for the 2014 season, if they even let you in with no racing credentials to your name.
However racing from a PS3 controller and real life is very different, these guys can spend an entire week learning a new track because there is no reset button for when they get it wrong. If you were to start now just with practice in karting and proper race cars, then the first time you hit the grid should be at least 3-5 years away if you spent every day practising. There is a reason these guys start in there early teens, by the time you get to 18, you just won't learn the same skills as you could as a kid, by the time you get into a car these things should be 2nd nature and no game will ever get you there, in fact your 6 years of racing behind a controller will most likely be the biggest reason for your failure as racing driver.