I am so sorry to hear.
I went through a simular situation. My dog broke his back. I spent the money for the surgery and timeless amount PT. He never recovered. I had to empty his bladder for him every 2 hours. I did this for almost a year. Then he lost control of his bladder and would wet himself a little all the time. He lost all control of his bowels. He had sores on his hind legs from dragging them. I tried shoes, socks and even made him a few things to try to help. I then started wrapping them twice a day with bandages. I looked at him oneday dragging himself through the house and he stopped and looked in my eyes. I could see his pain. His quality of life was terrible. He was only living.. and I was being selfish and keeping him alive because I couldn't bare to let him go. I finally made the terrible decision to have him put down. It was one of the worse expeirnces I ever went through. I will never forget that day. I sat and held my baby until he closed his eyes and stopped breathing. He is in a better place now..happy.. He can run and play no more pain.