As per the details you have submitted, your symptoms clearly telling that you have been suffering from GERD gastro esophageal reflux disease
Due to eructation of the gastric contents you are getting this gastric contents into your mouth...so I advise you to continue combination of OMEPRAZOLE
OTHER METHODS TO AVOID REFLUX:
1. Taking divided mini meals 5 times a day in small quantity
2.avoiding spicy, and junk foods
3. Keeping extra pillow behind your neck to avoid reflux of gastric contents
Hope this will help u....