Help Save My Puppy Gravy

Today my neighbors German Shepard broke our fence and got into our backyard. My almost two year old sister ran up to the dog and my mom quickly snatched her and brought her inside. In the process of doing so my mom heard a scream outside and the German Shepard had my little dog Gravy in her mouth. My grandpa opened her jaw and got Gravy out and my mom rushed her to the vet on her way she called me. My heart has never sank as much as it did when I heard what happened to Gravy. I was meeting her at the emergency clinic but she had made it before me. When I got out of my car the first thing I saw was vets carrying my poor screaming dog. 
The cost of the procedure is estimated to be around $3,000. A family friend was kind enough to pay the downpayment of $2,000 which I will be working to pay back. The big issue is they don't have payment plans and if I want to pick up Gravy from the vet I have to give them the remaining balance in 3 days. I'm 19 years old and I just don't have this kind of money. My family can't help because they struggle so much as it is. 
I lost my first dog Sam two years ago, he had a brain tumor and there was nothing we could of done for him except put him down. Gravy has an 80% chance of living, i can actually do something this time but my financial struggle is in the way. Gravy means so much to me. Whenever I would have panic attacks she'd always sprint to me and sit by me and comfort me.  She has such a big goofy personality for such a little dog.   I'd be forever grateful for a donation no matter the size. Please help me.