My doc says I've got esophageal rupture. What does this mean?

Break in esophagus. If you were hospitalized and operated on, most likely this is what happened. If not, "esopageal rupture" may not be the right term. I wonder whether one meant esophageal hernia, which is not exactly a rupture but a weakness in the diaphragm sphincter. Sometimes in communication, encoding and decoding the message can be the source of misunderstanding.
Not exactly sure. Esophageal rupture is unusual and indeed if you had it, meaning a perforated esophagus, you would likely not be reading this but rather would be in the hospital on the way to surgery. Likely, your doctor told you that you may have a herniation in the diaphragm resulting in a hiatus hernia that may predispose you to reflux.