J.H.
My dog died three weeks ago Saturday. I didn't have the chance to sit next to her and hold her, or pet her as she left this world. I didn't get the chance to do anything for her. I went to bed not knowing anything was wrong with her, thinking she was getting better. I woke up the next morning to a daughter screaming hysterically and dead dog laying in her crate covered in her own waste.
Your last image of your cat is a peaceful one. Mine is not. Your cat was old, and died humanely. My dog...God only knows what happened. My dog was 2 years old. The vet thinks it was Parvo...and now we're on high alert watching our other dog to see if she's next.
Please know that what you did was the most humane thing you could have done. If you continue to grieve like this, you might want to seek professional grief counseling. This is not healthy.