You released him from pain and suffering. It was an act of selfless kindness. You honored him greatly.

*hugs close*

Oh, angel... I am so sorry to hear that. I know exactly how you're feeling.

*nuzzles softly*

Twenty years is very old for a cat, though, so he has lived a good, long, full life, and you have been able to give him your love until the very end. I know that he has been grateful to you that you not let him suffer, and he is waiting for you at the other side of the Rainbow Bridge for the time when you will be reunited again, angel. And until that time, he will be looking down at you with a purr

I have had to put down a cat of 19 years. I knew him for 3 and he attached himself to my heart and dug his claws in deep. It hurt when we had to do it, but it was for his own good, he was in pain and that was not living....I understand Three years is nothing compared to 20..but I do know a little of that pain and can imagine what it would be for 20 years..so my heart goes out to you and I hope in time the wounds of your heart will fade leaving you with nothing but fond memories of your feline family member.