I feel your pain. We just burried our 15 year old cat yesterday. We had to put him down two weeks ago, but just got the remains back from the vet. Its is HARD. It is amazing how much we can love an animal. I know he had a good life and at 15 I can't complain, but that doesn't mean I don't miss him terribly.
For those people out there without pets... I know they don't understand WHY we even want them in our lives. All I know is that THEY are the loosers. The pain we suffer now is worth it as we enjoyed many years of joy of having a wonderful companion.
May our friends rest is peace,
André