Puppy Femur Surgery - Hit&Run

Last night at 1:30 a.m., a lady hit my golden retriever, Jake, with her car.  According to a witness, she looked outside the car, saw it was a dog that she hit, and took off.  My dog limped back to my house with his nose and eye bleeding, and with no use of his back left leg.  I immediately brought him to the 24-hour veterinary hospital, and they required me to pay 75% of their $1,200 estimate before they took his vitals and stabilized him.  Overnight they worked on xrays to see if he was internally bleeding and whether or not his leg was broken.  

His femur is fractured in multiple places and is displaced.  The surgery is estimated to cost an additional $3,000.  They will not perform the surgery without at least 75% of the bill paid as a deposit. My parents are not in any financial position to help me with the cost of this surgery so I'm asking for any help I can get.

I already have Care Credit and unfortunately it has no room left on it, and I was denied an extension.

I'm a full-time college student and cannot physically afford to pay this much money.  

Unfortunately, my four-year old Golden Retriever had to suffer so much pain due to a woman who left him as soon as she realized what she had done.  All we want is for him to come home to his family and be healthy.  Amputation is not an option and we do not want to put him down.

Please help if you can.  It would be greatly appreciated.