All you pretty much have to do is access the official web-site of the state you were born in. They should have something pertaining to obtaining official birth certificates on the site. If they don't, they will at least have a telephone number you can call. My mom was in the same situation as you were last year before our cruise. The state was really nice about it too. Most likely they'll ship your official copy of your birth certificate via FedEx, and you'll most likely recieve it within 36-48 hours of them mailing it out.