Burning sensation RT upper Abdomen & pressure, yellow/brown greasy foul smelling loose stools, gagging at times, loss of appetite. Queasy at times.

How long? How long has this been going on? If it is a chronic problem, you may have a problem with your gallbladder, which can be investigated with an ultrasound. It also may be to do gastroesophageal reflux disease, or GERD. It sounds like you should be seen by your doctor for an in-person exam and further testing. .