Jillian JillianJillian wrote:

And it is my responsibility to make sure he doesn't spend his last
days with me in pain.

I've only had one cat put down. I was asked if I wanted to hold her
while the veterinarian injected the drug. Being aware that there are
potential problems, I wanted nothing to go wrong so I said No and let
the vet tech hold her. All things considered, it was amazing. It looked
instantaneous. If she felt any pain, it lasted no more than a fraction
of a second.

That cat was special, but nowadays there are plenty of starving and
beat-up cats to rescue from the not-so-great outdoors.