Oh, I'm so sorry to hear that, and I know exactly how you feel. *hugs* My beloved Siamese baby went almost exactly the same way at the finish, and at exactly the same age too -- six weeks short of her 17th birthday. She'd been kidney-ish for a couple of weeks before she just stopped eating and drinking; by the evening of that day she was vomiting every few minutes with nothing but a bit of white foam coming up.

As she'd always been hysterical about cars I got the vet to make a house call. She went to sleep in her basket and never woke up again.

It's been ten years and I still choke up a bit when I write about it. Like Billy, she was very affectionate; used to follow me around like a dog and actually learned to walk in the direction I was pointing my finger, and jump into her basket when I told her to. I still miss her. I'm so sorry for your loss.