Help my Bentley boy get the surgery

Bentley has been diagnosed with hyperparathyroidism and needs a surgery to remove the tumor. Price ranges from $4000 to $8000 dollars. This is life threatening and if I can’t raise the money within the next few days he will need to be put down. I maxed out my care credit card and spent $700 on the testing for the diagnosis and now I’m out of options. I applied for an emergency animal grant to help me but fear it will be denied because they have very limited means as well. My boy is suffering and needs help. Anything helps.