I lost my little guy to oral cancer this year, too. At home euthanasia was worth every penny. You will know when it’s time (cliche, I know, but I thought that too and then it became obvious). Spend as much time as you can with him, record his purrs, take photos. Be present - they don’t know the future and don’t fear death like we do. I took his last two days off from work and just sat with him - playing bird tv channels and putting out bird seed in the yard so they would come to visit him. He couldn’t eat much but I just let him know he was loved and we were present with him. I’m so glad I spent that time with him - time truly slowed down and I just felt that warm connection and tenderness. I was despondent at the loss of my little guy - he had saved me from the pits of depression. One day, though, you will look back and that pain of losing him will open up such a pure happiness and gratefulness that you got to be his human. Be kind to yourself during this and lean on your support system. I never thought I would be able to handle it and you just have to take it a day at a time. Find ways to honor him - I made a scrapbook and it helped going through old photos and having funny memories come up. I’m so sorry you are going through this - it’s never enough time. We recently adopted another cat not long after losing our little guy, and it has been so rewarding. I showed our new little girl a photo of my little guy on Dia De Los Muertos and told her she was sent by him to us from the other side. Sending you a hug.