I am sorry to hear you are having kidney issues. The moderators at this site are very helpful and kind. Hopefully someone will be along soon to add to the information you have researched.
I have PKD and my doc is extremely sensitive about weight gain. If I gain even 2 lbs. he mentions it and circles my weight on my chart. It is so hard to control your weight while taking steroids. I see you are on Cozaar so I assume your blood pressure is under control. I hope you can get in to see the nephrologist soon to discuss your case. But on the other hand if you don't get in until December it means that your case isn't severe. Keep us updated.