@paulitee: I want to comment on your self-diagnosed insillanoma vs. your symptoms. Your symptoms may be caused by another culprit. If I were you I would have an Abdominal CT scan searching for kidney stones or gallstones as the culprit of your pain. A KUB ultrasound would also reveal location and size of stone, tumor, etc. in the kidney/gallbladder/bladder including any obstructions within the tubes (gallbladder or bladder urethra).
I speak as a bilateral kidney stone patient who remembers the flank/back pain well. Once you have verified your problem there is medication to help you plus surgical procedure if needed. An experienced Urologist will give you guidance.
Best health to you… dbamos1945