Upper Abdominal And Chest Pain, Upper GI Endoscopy Done, Shows Hiatal Hernia, No Acid Reflux, Pressure In Solar Plexus

I have been suffering from persistent pain in the upper abdomen and chest for over 10 years. Because it gets worse with exercise, I have had every possible test to assess my heart health (including cardiac catheterization ), and it has been concluded that my hearth is healthy. Later, I had upper GI endoscopy , and it showed a small hiatal hernia , but there was no erosive damage from acid reflux , nor do I have symptoms of acid reflux. The pain manifests as a pressure at my solar plexus, just below the breast bone. Bending over makes it worse, as does sitting down. I am most comfortable standing or lying down flat on my back. W