When I first moved to London in 2002, I was quite self-conscious about being one of 'those Americans'. You know the ones. They talk really loud in restaurants so everyone knows the status of their relationship or their day's activities. They wear trainers (that's sneakers or tennis shoes to my American brethren) to walk around London, as if they might join in a marathon at any moment. They are dressed very sensibly and never have an umbrella, but don't need one as they are wearing a waterproof poncho.
One of the things I tried to tone down was my usage of American phrases. Nowadays, my sentences aren't littered with 'like' or 'awesome' like they once were. But every once in a while, I bust out with 'dude' or pronounce 'whatever' in a valley girl accent. I'm not fussed anymore. I think it's what happens when you have kids. You lose a lot of self-consciousness and are more happy with who you are. At least I am. Are you happy with who you are?