I honestly don't think it's like that. On the whole, you've been accepted here. But, national pride/patriotism is an emotive thing, and the rivalry between Limey and Yank is nothing new. Try and keep it personal to the cunt you're sparring with, and avoid making it a clash of nations. That's bound to bring support to your opponent, as it would in reverse if it was one of us on an American site.
In the meantime, to try and make you feel better, my favourite American culture joke...
..What has eight legs and a huge black cunt?
The A-Team.