Help save my emotional support dog

Hi my name is Sheila my support dog was brutally attacked and bitten by my neighbors Pit bull. His dog has jumped the fence before and bit my other dogs. Due to his negligence his dog continued to get into our yard and cause harm. I was in the process of getting my yard measured so I could get a fence put up, the attack happened the next day due to carelessness of the pet owner no leash no fence no type of security for his dog. His dog once again entered my yard and attacked my 6lb Bishon Frise’ causing punctured lung, punctured liver and his intestines is out of the stomach cavity. My dog name is 1800 my husband bought him for me when my mother Passed to help me cope with the loss and now my husband has passed my 1800 mean so much to me and I would really appreciate any help I can get.