Huge hugs Blossoming - obviously I have no professional expertise, but it the change in kidney function that matters.
Yours may be less than it should be, , but is it significantly worse than say 12-18 months ago?
I was told mine was not good about 4 years ago, but nobody followed it up and TBH I feel pretty much the same.
Of course you can do the obvious things like cutting out salt and keeping hydrated, but I think what you need is a chat with a “Kidney” nurse after your next blood tests to find out a) whether you should be on any medication , b) if they want to take any action or c) if it just a case of monitoring in the short and long term.
Do not get despondent - while there are parameters which may ring bells for the professionals, you are often the best judge of how you are - if you don’t feel ill, try to relax and not worry.
(Because of his immunosuppressants and other medical history, Paw’s kidney results were often poor but they were normal for him - so try not to let it get you too down 