Oh no. I couldn't believe what I was seeing. I knew Willy was so young.
My Taz was diagnosed with renal failure shortly after he had surgery to remove some sacks that were surrounding his kidneys. I believe there was more to his health than I knew. Or the surgery brought on the failure. Not sure, but he was around 14/15 years old at that time. He did not make it a year.
But I know there are lots of others here on Pet Talk that have had (and still have) cats that are staying strong through the years. I remember reading somewhere recently (can't remember who posted or where I read it) that their cat was diagnosed 5 years ago. With proper care (and I know you will give proper care) Willy can be with you for years to come.
It might come down to you needing to give him sub-q fluids at home. Have you done that before? I had read about it here on PT and thought I'd NEVER be able to do it. I did it with Taz and it wasn't as bad as I thought it would be. They seem to know it helps them.

I will be thinking of you and Willy.