Oh come on Hassan, there are weird wankers in real life too. It's very obvious to anyone on that place now, that he is the fake and you are the real one since your face matches the youtube page and he is hiding his.
Don't go leaving the net, do you think backing down is going to make it go away? he will pretend to be you even more so if you just leave.
Is there an admin or the like over there that you can talk to about having his account suspended?