Please help me save my best friend

Hello my name is Breanna I’m 20 years old I just turned 20 , I had just left my job because of a big situation and I never knew this would happen to me , I took my dog to the dog park to have fun with him because I’ve been going through a harsh breakup so I thought maybe going out doing stuff I like can help my mind so I took him with my friend and her dog to the doggy park and when we brought the dogs nothing bad was happening a lot of puppy’s and dogs came up to my dog and I didn’t mind but this big dog came out of no where and grabs my puppy from his neck and starts shaking him trying to kill him and everyone starts grabbing the big dog and my dog was having a seizure my friend grabs my dog runs to the car calls the hospital I call the cops and the cops said they couldn’t do anything about this guy the guy ran off I tried getting his plates but he was to fast I don’t know what to do anymore because I had payed everything I needed to pay for him to at least get injection x rays and all that came out to be 1,000 which was what I had saved the doctor told me he has three features which is why it’s that expensive, I don’t wanna have to put my puppy down because of a situation that wasn’t my fault please help me i need help my family doesn’t have the money to help me either and I didn’t qualify for a loan

This money will really help me save my puppy , he’s been helping me more and more with this breakup and this life that I’ve been dealing with , now without him I feel hopeless