I am so sorry to hear that. I don't believe it's kidney failure. A kidney failure that would be final doesn't come just like this-not with a meowmie like you who gets regular check-ups for the kits.
And a cat in final kidney failure will NOT kill your carpet and be up all night in an aggressive way. (So you may take that as postive sign although it hardly is).
I hope the poor girl begins to be better. And that you can relax a bit too.