I agree with the suggestions to hang out with the right crowd who will rub off on you and to exchange the word with any silly one of your choice – e.g., “what the snapple,” “oh, shnitzel.” We’re not asking you to drop your friends. If you start showing that you’re working on this, your friends will quickly learn to appreciate and respect you for that, and maybe even abstain from using coarse language in your presence. Ok, maybe it won’t happen so quickly. But it will happen, even if you don’t notice it. A refined character commands respect from others without even trying.
Take it one word at a time, or maybe one hour at a time. You got this, girl.