For about a week i have had sharp pain in my upper right abdomen, its tender to touch and hurts a lot worse when i eat or drink. what could it be?

See your doctor: Right upper quadrant pain has many causes. Common ones involve the gallbladder. However, many other things can give the symptoms you describe. Further, your history of endometriosis adds possibilities to the list. It would be a very good idea to see your doctor and discuss these symptoms, as further testing is likely to be beneficial in sorting the cause out. Please see your doctor soon.