what could be wrong with my car?

I got my car back out of pawn this week. It was placed in pawn in May 2014. I get to my car and there is like 2inches of sitting water in the floor boards on the driver side, they left the Windows down. Vapor like mist was coming from my heater vents. Fog was not going away from the windows. He said he had water in it. I knew this was a problem cause before I pawned it I had a slow leak from the antifreeze.refill about every3 days but still had good temperature and ran back and forth to workll an hour each way no problem unless I needed to add a little water. When I go it out of pawn I drive this car going back to my home and it doesn't last 10 miles before everything just stopped. Lights didn't but power steering and when I put water in the reservoir I heard hissing by the engine. My email is [email protected] of I need more details