Scars leg surgery

Me and my fiancé rescued this poor baby after he was attacked my a dog. He drags his legs behind him and scoots on the floor to get around. We took him to our vet today and got x-rays. The results were devastating. His thigh bones are completely snapped off at the hip on BOTH legs as you can see on his x-ray.  Our vet said he had never seen anything so bad and that he was not capable of doing the surgery, so we took him to Wilson veterinary hospital and this is where he will be getting his surgery. Unfortunately, the surgery will cost between $2,500 to $3,100 which right now we cannot afford!! Fortunately we were able to apply for care credit cards so we can make payments and we won’t have to pay all at once. But we only got approved for $1,700 so we will have a good chunk of out of pocket cost. Ive never set anything like this up before but if this little guy doesn’t get the surgery we have to put him down which our hearts is not capable of doing. If anyone is able to help us and this little guy out we would be ETERNALLY  greatful!