Very sorry for your loss. My very first cat passed this past spring. You don't realize how much a void it will leave in your heart. I still expect to see her some days. The only thing that helped me was getting a kitten after a few months. But it still hurts.
This is not the greatest Thanksgiving day. I had to put down my 12 year old male tabby cat today. He was suffering very badly from a systemic infection in his little body and he was just miserable. He passed away this morning. His name was Peeker and I miss him already.
You'll start to miss all the annoying crap he did. That what happened when my dog died. Haha no more spaz running around the house every time something exciting happened. Though you know they say the best way of getting over a lost member of the family is to get another cat!