have you talked to a doctor?

Doc might know.

Idk whats that..but I hope you are ok hun

This sounds like stomach bile coming up through the esophagus. There could be a number of root causes. The main cause is diet. If you consume mainly overly processed foods high in fats, yhis can cause yhe over production of stomach acid, and when you kay down for sleep, all that extra acid needs to go somewhere, which leads into the second possible cause: erosive gastritis. This is where the flap in your esophagus weakens and can not close all the way, which is meant to keep all your somache stuff in your stomache. This can be weakened by overconsumption of caffeine. I would attempt to cut WAY back on caffeine and overly processed fatty foods if possible. And as always, if it troubles you, ask a medical professional sooner rather than later as this could be a sign of other more serious issues such as ulcers, which you do NOT want to leave untreated. They can get real bad real quick