Keep getting pain between ribs lasting 2-3 days goes then back.gnawing pain, better after food, wakes me up.back hurts also. stomach ulcer likely?

Not likely, but...: it is not likely that you have an ulcer, but with symptoms such as that, it is certainly possible. For now, I would avoid aspirin, ibuprofen, and any over-the-counter pain relievers except for Tylenol (acetaminophen). I would use over-the-counter antacids such as Tums whenever you have stomach pain. If you find that you need antacids more than 2 to 3 times per week, I would see your doctor. Good luck.