Mister cat's leg surgery

My sweet cat had gone missing a few weeks ago. My kids and I put up signs, walked all around looking for him, and asked everyone we saw if they had seen him. Until Saturday i saw him posted in the lost cats website on the auburn humane society. I was estatic to have finally found my boy. Until we got there, they informed me he had gotten hit by a car and a Good Samaritan had witnessed it and took him to an emergency vet. He currently has a broken right femur and two bilateral pelvis fractures. He will need his right leg amputated. Unfortunately I do not have extra money for this surgery. My sweet boy is only 6 years old and I have never seen a better pet. He's wonderful with my children, he embraces love from dogs. He is genuinely a one of a kind cat and a part of my family. He deserves to live and I know he will still be just as great with three legs. I appreciate any help offered.