So sorry for your loss OP.
I lost both my cats a couple years ago. One died in my arms Thanksgiving morning and I found the other dead on the floor 3 days later.
They were old and I didn't have the courage to get them euthanized (I was a train wreck at that time in my life and some days they were the only company I had, with their unconditional love and all).
I've since forgiven myself but that along with a heavy drinking problem and in the depths of depression, it was the lowest point in my life... but with some time, reflection and a little positivity, I forgave myself, let them go and moved on. I had, for the most part, given them a good life. They were both strays and had a better, more comfortable time here then they would have had otherwise... and I thought that was a very comforting thought.
Since then I've donated 100's of dollars to help save animals that have been injured by things like being hit by cars and other accidents when their owners didn't have the money to pay. That is something I'd have never done had I not experienced the pain of losing my cats the way I did. So in the end, I healed my pain by healing another's pain.
So, Coco and Princess didn't die in vein and it helped me gain a new perspective on life and death and finding a way to make sense of suffering. They had to die the way they did so I could learn a lesson and help pay for all those other animals surgeries, to help end their suffering, the way I should have done for my cats.
I just wanted to say that I know how you feel, at least a little bit, but try not to despair too much. Focus on the positives like how you gave them a good life, good food, shelter and warm lap to lay in, I'm sure your cat appreciated it :)
Keep your head up and find a way to make sense of your pain even if it seems futile and pointless right now. I don't know if this post will help you feel any better but I hope you do find some peace.
