I am so very sorry to read this. You are doing the loving, right thing to let Willy go now, but it is still so sad and heartbreaking, especially at his young age. We are sending our prayers and loving energies to you and Willy and all who love him.
May Willy's passing to the Bridge be peaceful and easy. He will be waiting for you there, whole and healthy again.
God bless you all.
Pat and cats
I've been Frosted (thanks, Elyse and Karen!).
I meant," said Ipslore bitterly, "what is there in this world that truly makes living worthwhile?"
Death thought about it.
"Cats," he said eventually. "Cats are nice."
-- Terry Pratchett, Sourcery