Jeff,
I am so sorry to hear about "Max".
I know how you are feeling right now as I am still grieving the loss of my 15yr old cat Tabatha (she just passed away a month ago). I agree with you...that was definitely the worst day of my life! I felt like someone ripped my heart out! She died during the night after having surgery to remove a tumor on her liver. After being up all night crying (knowing that she was alone and scared in a cage at the vet's office just about killed me), I got a call in the morning from the vet telling me that she passed away. The worst part was that my husband was not even here.
He was downtown setting up for a big weekend car show (Autorama). It was just aweful having to call him and tell him on the phone. We have no children, so she was our "baby". She just adored my husband and followed him everywhere he went.
Like others have said, take pride in knowing that you gave him a good life and I'm sure he knows how much you (and your family) loved him.
Take care,
Rita