save my cat phish

my pet cat named phish is my best friend, he was born with genetics that have essentially caused him a dislocated knee cap (medial patella luxation), he has also suffered a ruptured cruciat. currently he can’t walk on one of his back legs and is having a hard time getting around at all. phish is going to need surgery that will cost $5000 to fix his left leg, eventually he will need surgery on his other back leg. me and my family don’t have enough money to pay for the procedure and my mum has also recently broken her leg which means she’s out of work for six weeks. the vets have told me if we don’t go through with surgery  the only option is to euthanise my beloved cat. He is only 4 years old. Phish is the only stable support system i really have in my life right now, i convinced my family to let me get him in a very dark time in my life and i don’t know where i’d be without him. i am literally not capable of loving anything as much as i love this cat. i truly appreciate anything you can do to help ❤️