Oh, Monty's Mom, my heart is breaking for you. I am so very sorry to hear about all you and Monty went through together.
My T.J. (my avatar kitty) was my soul cat, the very heart of the center of my ever-lovin' momcat heart. The bond he and I shared was extraordinary. He also had what we suspect was a brain tumor at the age of 16 1/2 years. I did everything I could to try to save him (including living in the land of denial for about a month) and then to help him stay comfortable. It was the first time I've ever had to let one of my furs go. I knew he would be the one, because he and I would have done anything to stay with the other.
I was fortunate in that my niece was our vet at the time and T.J.'s death was very peaceful. I wish Monty's had been, too. I am so very sorry.
I now work nights at the front desk of a busy, world class veterinary E.R. I've been working vet E.R. night shifts for seven years now, so I witness a lot more farewells than the average clinic worker. We're available 24/7, so nights and weekends are especially difficult. I have never witnessed a euthanasia that was anything but peaceful, and I it's heartbreaking to know that Monty's was so traumatic for you. He is at peace now, and I know he understands that you made the most difficult decision you could make in order to prevent him from suffering a moment longer. I know that he would tell you that he's grateful that you did everything possible to help him.
Please try to hold on to the wonderful life Monty had with you, and how much love you shared for sixteen years.
I wish you a gentle healing from this crushing sorrow now.