Complex medical history with unexplained right side flank pain, Ideas?

Im 21 and have Lupus, RA, secondary Sjogrins, acquired platelet dysfunction, Gastritis and the fun things mixed in. For a year I have had this side pain that at first came and went, heck didn’t get notice for months it wasn’t there, then around 8mo came back but constant at this point. None of my diseases are under control. I feel like it fluctuates depending on bladder fullness, urinary movements but no signs of it. My rhuem suspects interstitial nephritis but saw a urologist who says not even a nephrologist would see me due to normal labs. I have had a CT, MRI,X-ray all clear from top to pelvis. It hurts all the time but can feel stabby. Doesn’t relate to what I eat, they did find blood in urine and high basos test but that is it. Looking into more GI issues or endometriosis but at this point I’m being told nothing can be done 🙁 right under my last rib going both towards my back and front.