Alka seltzer disperses gas. If you can't take that sort of thing, milk will sometimes help a person burp (release gas). Google online a list of non-acidic foods and eat a meal of those. To calm an acidic tummy, ice cream actually tastes good to a sick person. Eat smaller meals several times a day. Activia yogurt, with acidophilus in it, is excellent for the digestion, the directions say eat a cup of it daily for two weeks...I ate a half cup daily and felt worlds better within a few days, when I had IBS. My doctor prescribed hyocyamine pills during that time, dissolved under my tongue, to stop bowel discomfort, but yours is in the tummy. Tums are better than nothing, but short-term. Some medications can cause a lot of stomach trouble, so take those after you eat to ease the burning sensation. Those would be my ideas.
Call your personal doctor, if it is OK, that you take tramadol or other pain killer in mean time. Do not take aspirin, it can worsen eventual bleeding.