Please help me with my cats vet bills

My pet and friend hurt himself somehow in our home about three days ago. The Vets told us that he has a torn knee ligament. My bud sparks is only 3 years old, and is a pretty laid back dude, and only really moves to chase the sun around our home, or to cuddle up on me while i'm watching T.V. so i'm not sure how he was hurt. The saddest part is that he needs surgery that I can't afford. I've tried to convince him to get a job with health care prior to the injury, but he just doesn't want to adult. In our main photo you will see him hiding his face in shame from not listening to me, once again. The surgery will cost around $2,200, and I am $800 shy at this point.