Very very sorry to hear abt your loss, my friend.
Made the same dreadful decision a few months ago. My cat of 5 years had cancer (lymphoma). It's totally, totally the toughest decision in the world even though it should be the easiest to choose not to let your cat suffer. My heart ached as my cat went limp. Even on the taxi ride there, my wife and I were tearing up. You're giving up a part of your life and it's tough but to hold on to her would be selfish.
I dread to make the same decision again but I know I will have to (got 5 more cats).
As for user111, let's just ignore him. By his actions, he obviously craves attention and the only way is to ignore him. I can only pity him for not knowing the unconditional love that a pet can give.