hey mate. first things first...realize that just because you have beliefs and other such thoughts about yourself doesn't mean that that makes you who you are. This is hard to explain but imagine this awesome gorgeous looking bloke [me of course

] comes up to you and says go up to that hot girl and start talking to her...and you say "nah man, thats not who i am" just because in the past you havent done so [you might of already] doesnt mean that that person is you. it just means you've never had the confidence etc. so its not changing you...turning you into some else. its actually more unleashing your full potential. some people fake it until they make it. that works for them.
what im saying is...your probably an awesome guy, show the world that.
take this view point too. society has made it so we dont dare go out there and talk to women. because we are programmed to think shit what if ppl laugh, what will ppl think of me? etc. but trust me, getting rejected means nothing. if you go up to a hot girl and talk and get rejected, guys will still think. woah, he has some mighty balls. noone will really notice either, ppl are too concerned about themselves rather than noticing a girl turn away from a bloke.
read the game, read mystery method. they are great starting points. learn inner game stuff so you are comfortable from within.
i will tell you one thing...we only live once, despite what you are told. make the most of what this small planet has to offer whilst you still can. get out there mate. enjoy yourself