I highly suspect it being an ulcer. Hunger pains are the main symptom. Some medications do cause damage to the stomach lining, especially advil, ibuprohen, tylenol, ect. I would really recommend going to a gastroenterologist and getting it checked out. It's not worth it to go on feeling that way - I understand, and it's incredibly uncomfortable. It could be a form of gastritis, but my guess is an ulcer. For right now, DGL (dgyllecerized licorice root) may help. It coats the lining of the stomach, and provides some relief for ulcer sufferers. It can be found at most health food stores(its chewable). Anyway, hope everything turns out ok
You may also have Helicobacter Pylori. Look online for more about this gastro infection. One of the things mentioned on Dr. Marshall's (the doctor who discovered this in 1994) website is hunger pains that won't go away.
I was diagnosed with this today. My symptoms seemed to start when I tood one too many anti-inflammary drug (like Aleve).
Good luck.
Jane in CA