Just wondering if your doctor has checked your pancreatic enzymes.  I have a friend with chronic pancreatitis and she cannot eat without pain either.  And the pain is horrible, she's been on heavy meds for years and sometimes has to be hospitalized to "rest her pancreas."  Hers started first when her gall bladder got bad, they took that out, and she was still sick.  It turned out to be pancreatitis.  This can be acute (short-term) and go away, or become chronic.  It is not cancer.  But it can be disabling. 

The test for pancreatic enzymes is a simple blood test for lipase and amylase.  In her case, eventually she got 'gastroparesis' stomach didn't digest, she had to go to complete parenteral nutrition, basically, a tube feeding, which she does at night.  She still does eat at times, but pays for it when she does!  But - hard never to eat! 

I hope whatever you have clears up!