Always look forward.
I know how you feel though, I always say to myself "man", I wish I learned all this when I was back in high school so that I wouldn't have screwed up in college so much.
Conversely, my older friends always tell me that they wished they learned all this back when they were my age. So unless, you're 65, you don't really have much of an excuse. If you really dedicate yourself, you can really solidify your game in less than a year.
Tell you what though, the more important thing is to be proactive. You can't change the past but you can change the present and future.
Start going out, start getting rejected, start taking girls on dates. In the beginning you can't control whether a girl likes you or not, but you can control your ability to open sets.
Just be happy you didn't have to do it on national TV
-Kevin