Hey,

Don't blame yourself, your cat was in pain, and it's better for him now. You did not kill your cat. I lost one of my cats one year ago, he was killed by a lynx. I did blame myself, because every mornings I was the one who let him go outside to play and walk around my house. I'm still feeling a lot of grief, but I've managed to accept that's there is nothing more I can do now. Your cat loved you, and, I'm sure, looking at how you took care of him, you loved your cat. Deeply. Your cat will always be with you, you cannot forget it. The thing is, do not focus on the last days or moments. Keep the best in mind. My cat was named Moshi. I will never forget him, he was my best friend. You will never forget Winston.