Oh forbesisnow2, makes me cry to hear your sad news. I know just how you feel, it brings it all back. The world seems divided into those who understand, and those who think "its just a cat". For us and you, they are part of our family.
We lost our much loved tortieshell Rosie just a year ago, age 14, and were devastated, it took us by surprise how much it affected us, and still does, but it eases. We have 3 cats left, all getting older, so I treasure every day with them.
I still say hello to Rosie at times (out loud when alone).
Your beautiful Panda was so lucky to eventually find such a loving home with you, I'm sure she knew that and loved you back, and as time goes on, you'll be able to rememer the happy times more. Best wishes x