What Causes Pain In Left Upper Quadrant Area Radiating To Back?

Question: I have pain in my left UQ that radiates to my back. My back is swollen and has been for many months now. Pain is variable. I do not drink due to my CRPS. I have had this pain now for more than a year. I have seen multiple doctors aand they all have differing opinions and diagnosis. I usually have no pain in the morning, but at the end of the day my left side is quite painful and I find it difficult to bend or lean to my left side. My appitite has diminished. My A1c is 5.9 and I am not diabetic. I do have episodes of nausea, but no vomiting. There is a confirmed history of my father having pancreatic cancer. I have had ny gall blader removed. The pain is mostly in my back, just left of my spine, and wraps around my left side. It is painful to palpation, both just off midline abdomen, and just below my ribs in my back. My kidneys tested clean, as did my spleen. I am at a loss, but whaat do you think? I would like tto add that lately, as in the last week, I have been experiencing headaches at the end of the day into evening/night. This is new, and is different from my migraines which are under tight control with my current medication. I am not hypertensive.