Similar issues.
I also tend to belch a lot and this causes me to struggle to breathe at times. The symptoms started with heartburn, then escalated to right shoulder pain and pain on my right side and then it got worse. It also comes and goes with me. I have an appointment with the hospital on March 3rd (too long if you ask me) with a surgeon and perhaps he / she can help sort out this mess.
It very well could be your pancreas as well. I have the same type of problem, only mine is tender to the touch and hurts worse when I lay on it. I am having a HIDA scan next week to determine if its gallbladder related or due to something else.
It could be a gallbladder problem. You should see a doctor who can run tests. They can test the function of your gallbladder (HIDA scan) and do a sonogram to see if you have any gallstones.
Yep, it could be gallbladder. Sometimes stones or sludge get hung up in the bile duct and cause these kinds of symptoms. Once it clears out, the symptoms go away - for a while anyway. :-)