We were grateful our cat passed away peacefully at home and on his bed some six weeks ago after 17 years and, whatever anyone says, it isn't easy! And this is from a 50-year old bloke who used to play rugby!!
The one thing we were adamant about, though, was that we weren't prepared to see him suffer and, if needed, we would have asked for him to be put to sleep.
I think the best thing you can do for any pet after such a long time is make their departing as comfortable as they can be when their time comes.
Today will be very tough Central Cake, but remember the life you shared with Misi and that you did the right thing by her when the time came and that is all any caring owner can do.