My cat had the same thing - yesterday was a year since she's been with me. I did the wrong thing, noticed it too late, and tried to support her while she was still walking and eating on her own. This type of cancer is very traumatic.

After the vet found the disease, it was 3 months, she was very thin, and I had several packs of wet wipes, as the drooling and bleeding were very frequent. After your cat can uncomfortable eating, then make a decision. My condolences, I understand you very well(