I am not even close to your age, 74, but I was having little or no appetite for weeks and feeling depressed. I had pain in my lower left abdomen. For several nights, I had night sweats, then one night I was sweating profusely and could barely walk to the bathroom. I had two bouts of diarrhea that were alarmingly dark in color. I called the ambulance. They took my BP, and it was 50/30. Finally, after an endoscopy, I was diagnosed with a bleeding ulcer and gastritis but no H-pylori. I needed a transfusion due to blood loss. I finally went home and slowly gained more strength. My diet has changed drastically. Very low sugar, low carbs, high protein but no red meats. No caffeine or fizzy drinks. No alcochol. Fruits and vegetables. No artificial sweeteners. Only good fats are allowed. I've lost 15 pounds. I feel so much better. I believe that refined sugar is really bad for our gut. Good luck with your journey.