I remember back then I could talk to people with no worry and it would be fine, until I got depressed I felt like I lost my social touch and forgot how to have fun during socializing again. Why is this?
Personally I can't really answer your question but I can convince you to step forward. There is no point in self pity it's a waste of time because in that time you could have been slaying chicks or socialising with other aspiring pua's but the big solution to you social problemo... Is to get other there and simply talk to people! Experience is the best teacher they say and who knows maybe you'll become your old self again or maybe you'll become better. And if you have approach anxiety just look in the best of the general section for one of light's posts he has a decent article on fixing that.