Try not to worry too much, Nandalot. Easier said than done, I know but careful tweaking of your medicines/dosages could well halt the decline. Someone I know was diagnosed with reduced kidney function in September last year. He's in his mid 80s and on a cocktail of meds for complex multiple ailments. It took 14 months of dosage adjustments, changes of pills, and monthly blood tests before his BP and kidney function stabilised but, a couple of weeks ago, he received the good news that his BP is normal and his kidney function stable and he need not return for a further check until February. Both physically and psychologically, he's feeling much better.
From my memories of my late sister's final months, I believe there are dietary changes which can help but these tend to involve reducing the amount of fruit and veg you consume which doesn't sound like a great idea. You'd really need a qualified dietician's advice before taking any action food-wise. (I should add, in case this paragraph has alarmed you, that my sister's death was NOT the result of kidney problems. The kidney problems arise due to medicines prescribed for other reasons.)
Here's a (((hug))) for the meantime and fingers crossed for you on Friday.
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