Hi,
Despite that, I'll try to provide - hopefully - helpful advice. Let me start with this: kidney failure does not cause pain unless it's been caused by obstruction. In that case the obstruction would cause pain.
A renal stone is the most common cause of renal obstruction. You haven't accurately specified the site of pain. I haven't understood whether the pain was in front (the abdomen) or the back.
Kidney obstruction may cause pain both in front and back.
Flank pain is expected when the stone is high in the kidney. As the stone descends down the
ureter the pain starts to move towards the front.
When the stone gets stuck right before the entrance to the bladder the patient may feel pain in the lower abdomen and may be accompanied with symptoms of the lower
urinary tract (frequency, urgency, etc).
If the pain is on the front only then the
gallbladder should be investigated. If you do know the cause of pain then taking analgesics is indicated. The safest for you is
paracetamol (which won't worsen your
renal failure).
If its effects are not sufficient a mild
opioid can be added. There are some formulations with combinations of paracetamol with opioids. All of the drugs that contain opioids are prescription drugs.
If the source of pain is still uncertain then the investigation is indicated.
Hope I have answered your query. Let me know if I can assist you further.