Hello thanks for posting at HCM. Since your are diabetic, we must rule out a cardiac cause of this chest discomfort. I recommend an ECG, 2 d echo and a treadmill test. This the diagnostic modalities will give sufficient information about the heart function, previous damage to the heart, any leak between valves and can also predict the possibility of cardiac event in the near future. Also since you have got bad breath all this can also be connected to hyperacidity in the stomach. I recommend a course of antacids twice a day for 2 weeks. Please revert back with the above tests. wishing you good health. Regards.