Wow...I don't know much about the surgery that you are going to have but if it is in the bile duct it seems that it would be something that you need out asap. Did you have an ultrasound to determine that there is a stone? Have you had an endoscopy? That would probably show what all is going on in your gut and esophagus. Get a second opinion if you feel that your Dr. is questionable. Where are you from? It shouldn't take 2 months to get on a surgery schedule, unless you are out of the USA. If you are in that much pain I would get a second opinion. You don't want to end up in the ER like you did the first time.
My Dr. suspects that I have reflux so he put me on Nexium. I never had very noticable symptoms, which I hear is very possible. But, yes I do know that the gallbladder, stones and GB Sx are all connected to reflux and even IBS. Once in awhile I do have burning/heat sensations in my chest and back. Symptoms vary from person to person.
Hang in there. We are here for you.