I Am Having Pulsating Pain In My Upper Left Abdomen,

I am having pulsating pain in my upper left abdomen, feels to be almost under my ribs and I'm also having upper and lower left back pain. I have had my gall bladder out and also had to have stones taken from my bile duct, as I was developing pancreatitis. That was 2 years ago. Ever since then I've had this pain in my upper left abdomen that continues to get worse, I also notice after I eat it feels worse. Any ideas in what this could be?