OMG I am SO sorry. Losing a fur kid is devastating at any stage, but to lose Pookie right after he got a clean bill of health must have been devastating.
This type of health issue can happen very quickly in senior cats, and although Pookie was not really old, 10 is considered senior. Our vet told us that they can be fine one day and then it can just hit them.
I love the photos in this story.
I hope that you will feel better soon. You will never forget Pookie, but try to remember all the fun times. Write about him. Lots.