Gnawing/burning feeling below breast bone after eat a light meal. No fever, lack of appetite, decrease urination. I'm always eating peppermint altoids?

Gastritis . Sounds like you have gastritis - an inflammation of the lining of the stomach caused my stomach acid. The decreased urination is probably due to you eating and drinking less because of the pain. See your primary care doctor or a gastroenterologist for additional work up. Ps - the peppermint altoids aren't helping you.