I have dry mouth, sour stomach feel like i want to gag,at times mouth feels like very watery than dry, and i had a mouth soar.

Get checked: This could be due to acid reflux, diabetes, or other problem. See your doctor and get checked. Good luck!

Mouth/stomach/etc: you will need a physical examination, possibly imaging, possibly lab tests, to evaluate your symptoms as they are common to a plethora of problems. If the mouth sore has completely healed after 2 weeks it was probably coincidental. If still present after 2 weeks requires further investigation. See both Dentist and Gastroenterologist.

It does sound like GERD, so after a discussion with your physician a dentist could make you a night guard or retainer to hold a protective night gel to counteract the pH problems that can destroy teeth. ‘Retainer gel’ is a generic that can be found online. Appliances can be made by most dental professionals.