Whoa, 19 years old? She lived a very long life! I can see why you're both happy and sad. Poor Kyller was in a lot of pain, poor little mite, and she was probably quite relieved to escape from the pain and meeting with Spider, floating around in the sky on a cute little cloud :3 All of the angels will be fighting over who will have her as their little pet, but of course Kyller will reject all of them and choose you, even though you can't see her anymore<3
Nonetheless, though, I feel really bad for you. A tear just slid down my face thinking about my cat dying. I have a little tip for you: Even if people say to just remember the good times you had with Kyller, try your best not to. You'll just start sobbing, remembering her. Watch a comedy or listen to music (not sad ones) - just take your mind off of the death however you can. I'm so shocked that you're strong enough to actually post this, I would be in my room just crying and crying.
I just listened to that song, 'Bones'. It made me cry a bit, thinking of your cat. But Kyller is in a very, very good place now, with millions of treats and she'll be young again :3 I was going to write more, but I'm turning into full outbursts of sobs now because I'm getting too depressed, so I'll wrap it up here. Stay strong (even though you are!) :3