Saving "Biggs"

Our 6 yr old miniature Schnauzer Rainier "Biggs" Is fighting for his life after a fight with a pit mix last week. He felt he was protecting me his favorite person. The other dog was much larger than he, and ripped Biggs esophagus, Larynx, and epiglottis free from his oral cavity. He also tore the skin from the muscle on the side of his sweet face. Post surgery Biggs is suffering infection, and necrosis. Whatever he eats or drinks comes out his drain on his throat. Without additional surgery Biggs will die and I don't think I can handle another loss right now. My father passed May 9th of this year. My heart is already broken. Please help. God bless you.