First: are you sure it's an ulcer? Maybe just stomac acidity... anyways, avoid milk (powder or liquid), coffee, chocolate, alchool and soft drinks. Too much salt is not good (avoid toyo and daing).
The good food for your stomach pains:
white meat (like chicken. NO red meat)
fruits and vegetable (carotts are excellent for ulcer)
seaweeds
eggs
yoghurt
tokwa
Drink mineral water (not distilled water)
Don't eat too much at a time... better to eat 5 times a day smaller meals than 3 times a day!