@becky1024 I echo what @nscappa has said, in that we are here to support you however we can. I also have an ultra-rare health condition, involving my kidneys, and have found that working with my doctors, doing my own research, and being "part of the team" helps me.

Dialysis typically is considered as a person gets towards 10% function, except in cases of sudden kidney failure. Gentle exercise, good healthy eating [low/no sodium, careful with potassium and phosphorous] stress reduction however you can, all can play part of keeping yourself as healthy as possible. Learn your lab numbers, watching trends not single results will give you good guidance. Many times declining kidney function comes on slowly, and our bodies learn to adapt to it, so it takes us by surprise when we realize how we may be affected. I feel fairly well at 13% function, but in looking back, I know my energy and "usefulness" used to be better. Now, add in my other health issues like being an active cancer patient on chemo, and I am reluctant to put all the blame on my kidney issues.

I do hope we can offer you support and ways to handle all you are going through. Have your doctors found any link to what your sister went through, and your case, to help you now? You have about three weeks before those tests, how will you handle your time and emotions? Have you thought about writing it all down, keeping a journal to sort things out? We are here for you, please lean on us!
Ginger