Go to your Facebook profile and copy your URL ID after https://www.facebook.com/URL.IDHERE123
Then paste it into the Facebook textbook on your BWH profile. And save it. It's that fucking easy! How the hell can Facebook find you if you gave it something that isn't unique?! There's most likely a chance that at least ten other people on Facebook have the same name as you, but not one of them has the same ID. It's common sense!