I Have Been Experiencing Acid Indegestion Every Day For About

I have been experiencing acid indegestion every day for about 3 months, it gets worse at night and lately has been keeping me from sleeping since it is so severe by bedtime. I have been sleeping propped up on 3 pillows. I have had an endoscopy and colonoscopy, all good, more diagnostic test to be done on my esophagus in several weeks. What would those test be called, something regarding swallowing.
I have been tweaking my diet to eleminate any acidic foods as well as foods that would cause a problem. How long after you eat something does your stomach acid respond and thus go up the esophagus. Just ate some papaya, which is suppose to be good for GERDS, acid is starting to burn my esophagus, had a banana about an hour ago prior to that a veggie juice about 2 hours ago. I'm trying to figure out why I'm already burning at 1 pm.