I have same symptoms, any word yet.
It might be that the pain comes from your back around your ribs into the cartlidge that the ribs join onto in the front of your chest right at the bottom just above the 'V' where your ribs stop above the abdomen. I had this for years and when mine gets irritated it feels like your pain and also i feel a hard lump just above the "V' in the centre of my chest about 3 inches long and 1 inch wide. It's very sore and if you push on it it really hurts. I think Its called chondoiteritis or similar. Its inmflamed cartlidge, and when its inflamed it upsets my stomach too. Maybe ask the doctor - lots of doctors tried to find out for me but only one finally worked it out. Hope you feel better soon.