I know it's easier said than done, but try not to worry because the worry will increase any acid in the stomach & make the symptoms worse!
I know this for a fact- I have GERD & my symptoms are much worse when I stress about anything at all!
The endoscopy will tell them what is going on- the sooner you have that done, the better! Meanwhile I wish you the best of luck & I will be thinking of you!
Please get back here & tell us how you went with the appointment.