What Causes Tenderness In Upper Abdomen Along With Belching?

Hi, I m a 61 year old male and I just had my 4th episode of the same symtoms. Feels like stomach is tender right under breastbone and lower. pressure and desire to burp to relieve pressure. in addition to stomach discomfort begins just below shoulder blades in back. cannot find a position to sleep in. first event lasted 5 hours but now full day.