I'm sorry to hear you haven't been feeling well Gry. My grandfather suffered from kidney failure, amongst other things later in his life, and my mother was hospitalized for a long period during childhood due to kidney problems.
From what I've been able to gather the main thing is not to put any extra strain on your kidneys. Cut back on sodium and anything that your kidneys will have to work harder at processing. An important thing is to stay well hydrated and drink plenty of water.
Cannabis has been a huge help as far as dealing with medical issues for me. I don't react well with opiods or opiates and often become very nauseous, even from small doses. Sleep aids and anti-anxiety meds also seem to cause more problems than they solve for me. It's disturbing that so many suffering patients have to fly under the radar with cannabis just to not be sick.
Wishing you the best for a healthy and happy future.