No insurance , for my surgery on Dec 5, 2019

I have not work since April due to knee problem,on Oct 19,2019 my left knee buckled up and tear my achilles tendor went to Dr. and need surgery since I have no insurance it will cost me almost 20,000 I already paid 4,500 so they could start surgery on Dec. 5 ,2019 at 7am any help would be gratefull it been done by Resurgens Orthopaedics in Kennesaw GA . Dr M. Shay Womack MD surgery will be for left foot(1)Achilles tendon repair with possible autograft;(2)calcanael osteotomy 
Thanks