Not to sound like the broken record (but meaningful all the same) that is this thread, I'm really sorry about your cat. You guys did the best thing for him (her?), both in giving it a home, and laying it to rest.
I had to put my first dog down back in November. He was 17 years old. His name was Shadow, an all black (aside from a stripe of white running from his chin to his chest) lab/beagle mix. I got him when I was 6 or 7. I'm 23 now. He lost his hearing, his vision was starting to go, his hind legs were slowly stopping to work, and we had recently found out he had cancer. The dude was a fighter, fiecerly protecting me and my family (he lost the tip of his ear protecting my younger brother from a much larger dog who had wondered into our yard). He was my best friend, my partner in crime. When I was smaller, I'd lie on the floor to watch tv and he'd run over to me and snuggle up, letting me use him as a pillow. I spent many saturday mornings watching cartoons like that. When we put him down...he just would not let the drugs take their toll. Word cannot express how hard it was to say, "Shadow, buddy, you've loved us enough. It's time to let go..." As soon as I said that, he looked up at me, winked (which he did alot to me), and closed his eyes for the last time.
I consider myself a pretty tough, "keep emotions inside" type of guy, but I lied on the vets floor for half an hour, just holding my buddy and crying.
I payed extra to have him cremated alone (they usually do mass cremations of pets). His urn and a picture of him sit on my night stand and I say "goodnight" to him every evening. I think I always will.
The family still has two other dogs and some cats, and as much as I love them, Shadow was the best, and I'll never forget him. Since then, I have moved into my own place, and I have realized how much we can take pets for granted...sitting alone at night watching tv is a meaningless time spent, unless you've got a dog curled at your feet.
I feel you buddy. Time will heal the wounds, and getting another pet will never replace your Ash, but like a friend, your next pet will help heal the pain.
...*goes to have ciggarette so office buddies won't ask why my eyes are watering*