H pylori doesn't cause these symptoms. It can be implicated in causing ulcers, not necessarily stomach discomfort. Most medication used by doctors for this cause a rebound effect, where the stomach just produces more and more acid in order to digest protein. I would try a bifidus based probiotic to replace the digestive organisms the antibiotic killed off, and DGL and/or aloe juice and digestive enzymes for the gastritis until you discover what in your diet is causing this and change it. Stress and anxiety, by the way, do cause this problem in many people, but not stress from a medical problem -- it's chronic anxiety that does it. That can be helped by meditation or breathing exercises and the like. I don't think this is an area where doctors are the best at treatment.
I really have no patience with doctors who ascribe an illness to "stress," "anxiety," or other catch-all phrases that actually mean "I don't know what is wrong with the patient."
I think I know what might be wrong. For your infection you were undoubtedly given lots of antibiotics. Candida albicans loves them. Aside from prednisone, it is its favorite food, if we don't count sugar.
I am now almost fully recovered from systemic candidiasis. I refused the fungicides because (1) if they work at all, they only work temporarily while giving birth to mutations and (2) they have nasty side effects. Instead I took Lugol's solution and oil of oregano and cut back on acidic foods. My digestion is calming down very nicely, thank you. The process is slow, but it works.