My sister had her gall bladder removed a few years ago, and I know what terrible pain she was in before they removed it. It must be terrible to still be feeling that way now. I am sure if the gastroentologist thought it was the stones in the ducts, then before worrying about anything else I would trust him.
My only other thoughts are maybe an intolerance to the foods that you mentioned, have you tried to eliminate them completely from your diet?
Stress can wreck havoc on our bodies and can make us ache in places we didn't even know existed before. You mentioned having a child with CP. I know a lot of mothers with children with CP and know the stress that they go through, so I really do feel for you at the moment. There is nothing worse than needing to be 100% healthy for someone else and feeling rotten. Do you do a lot of heavy lifting, this could also explain aches and pains in the place you described?