1. ANXIETY due to pain of Gastritis could result in Tachycardia,otherwise can't think of any other reason causing rapid heart rate
2. because you have a light Barrett syndrome
that means Endoscopy was done and pathology in lower esophagus was detected.
3. could be possible Gastro esophageal reflux disease
(GERD) due to lax lower esophageal sphincter (LES) resulting in reflux of acid back. (reflux esophagitis
4. avoid foods which are difficult to digest like oils and fats,which make stomach to release more acid,avoid tea,coffee,smoking,alcohol,sour foods (pickles,tamarinds,vinegar,curd)
5. fibers are necessary in the diet as they help in the digestion.
6. eat slowly,avoid haste,chew properly and avoid over eating.
7.check stool for worms, hemoglobin for anemia,ultrasonography
of gall bladder,gastroscopy for H.Pylori infection