Rear end drivers side binding when driving. Started after I backed up two feet and heard a snap

First off I just recently bought the car and when I did they stated the parking brake did not work after having it for two months I happemed to back up and I heard a loud clunk and then alot of noise coming from rear. Then it went away for a few days but now I drove it and it feels like the tire is about to fall off. It totally makes the car sway and the right rear bunds up please help