I have dealt with a ton of U.S. bashing in my time in the U.K., it's luckily mostly from strangers/people I randomly meet, so I have learned to keep my head down. I ALWAYS feel like the loud American, even if I am just being me, in some circumstances. Like if I forget to ask for "TOMAHTO SAUCE" and say ketchup I will get a rude/attitude response in a restaurant, little things like that. British people love to feel superior to Yanks, even though their country is in the shit too. I also live in a city that attracts rich asshole type Americans for work, so I avoid them like the plague lol. Once people get to know me it's fine and most of my friends were very welcoming and kind from the start but I was lucky in that my husband has good people in his friend group, not anti-American types lol. That is so cool people think you are from there, I almost never "pass" lol.