When/If he shows up at your house with his buddies, say this: "I told you online, I'm not interested in going out with guys! Now leave me alone!" That should go over pretty well.
You could fight him 1-on-1, and the loser has to buy drinks for everyone. Or, you could just let him kick your ass. That would probably stop him from harrassing you any further.
Either way, start working out now. Cuz you'll probably give out your phone number/address to a stranger again in the future... and you'll probably want to be buff when you have to fight again.
dfi
p.s. there are no girls on the internet, only guys posing as girls.