Re: Wierd Pain!!
GERD means Gastro Esophageal Reflux Disease. It involves the "backward flow" of stomach contents into the esophagus. It's really a new term for old fashioned heartburn, acid indigestion or hiatal hernia.
Hiatal hernia occurs when part of the upper stomach herniates, or bulges, into the chest cavity. I'm not sure if you have this, but it's a possibility since you are having some chest pain.
I think the "water" suddenly coming up into your mouth is known as "waterbrush" due to excess acidity in the stomach that comes up the esophagus into your mouth.
If your own doc didn't address this possibility, see a gastroenterologist.
Simple lifestyle changes, especially regading diet, sometimes combined with medication, can treat most cases of GERD.