Is there a doctor in the house? Pain Problem.?

Was looking for some professional advice (I have a week to wait for a Doctors appointment!) I had my gall bladder removed about 1997 and have been symptom free since. (Actually my gall stones never caused me any pain and it was a surprise when they were discovered!) However, over the past two weeks I am in chronic pain in my back (not stomach) just above my waist, when I eat anything with even a remote trace of fat. Minutes after eating the pain starts and I sweat etc, and sometimes want to vomit (I can't due to not being able vomit after Hiatus Hernia surgery, so just go through the motions of being sick). But the pain is excruciating, and I have to take pills like Tramadol and lie down until it pes, but it can last for hours! It's getting I am scared to eat anything with fat/oil in it at all. What can be the problem, if my gall bladder has been removed? Can a stone still form in the bile ducts? And why is the pain in my back (just below the rib cage) as opposed to my stomach? Thanks for any (sensible) advice. I was 42 in March.