Had to put my cat down on Monday. She was with me for at least 18 years. That morning was rougher than I expected. I've lost several pets and all four grandparents without shedding a tear, but this was much harder.
I put on a youtube video of birds for her to watch, as I had many times before. Seeing her watching it as if she wasn't feeling sick, knowing it was my last day with her, it fucking broke me.