What should I do, what've i done wrong?

Don't do anything, and no, you havent done anything wrong. Remember this, as it will help you with any and all future men in your life: When a man likes a woman he will PURSUE her. Anything else is just that, anything else. Let this man pursue you. If he doesnt, he changed his mind for no reason, and he's not interested anymore. Also, being on these social websites too much just doesnt allow for any privacy, so now he thinks that anything he posts, you, and all other women will see. He doesnt know how to respond to that, so he just ignores it. Good luck. p.s. I don't have a fb account just for that reason, and even if I did, I wouldnt be on it.... It's a turn off to me for that very reason. Good luck.