GERD? Ulcer? Acid Reflux?

Hello! Recently for the past week or so I have had a burning sensation in my stomach (NOT MY CHEST), burping frequently, cramps like pain around my stomach and chest, nausea but can't throw up and a small amount of diarrhea (not often). I have been to a doctor and was prescribed Zantac 75mg and have been taking it for the past 3 days (not much improvement) Should I take the medication longer or may I have something serious. I think I may either have Acid Reflux, GERD, or an ulcer. Please help!

If any could give me advice, I would appreciate it. I have had constant mucous for one year. I was diagnosed with chronic sinusitis. After many unsuccessful rounds of antibiotics, an ENT performed a sinus surgery. This surgery did not help whatsoever. I cannot tell you how many doctors I have been to try to get well. The mucous is also in my throat. I have developed a burning tongue, ulcers on the tongue, a sour taste in my mouth, weazing, and cold like symptoms. I had an endoscopy performed 9 months ago. The GI dr gave me some medicine and did not seem concerned. I kept getting worse. The ENT ordered a swallowing test that shows a small hiatal hernia and severe acid. I went to a surgeon yesterday and the dr spoke of doing the Nissam surgery. I noticed his office had many patients seeing him for bypass surgery to lise weight. I was extremely upset when he told me how I would have to eat after this surgery. I couldn’t go to work today as I cannot continue living with this awful condition, yet I cannot fathom doing the Nissam surgery. I am desperately looking for another treatment for this condition. Additionally, the surgeon had not heard of acid reflux causing sinus issues. If anyone could help direct me of what to do and where to go, I would appreciate it very much. I live in Orange County, CA. Thank you!