Swollen pancreatic head may be chronic pancreatitis
, but this should be confirmed by increased pancreatic enzymes in blood.
Chronic lymphocytic gastritis may be connected with H. pylori infection or with celiac disease (even, if you have no symptoms).
I recommend you have a BREATH (not blood) test for H. pylori, and if positive, treatment with antibiotics.
The next possible investigation would be duodenal biopsy to check for celiac disease.