Overheating and water comming out exhaust

Hi please help I have a subaru impreza 2.0 turbo 99year 100400miles the car started overheating no leaks but the water was being lost out the overflow pipe when the engine got hot around town. So I replaced the themostat and still same problem, then I took the themostat out and then the car was fine around town for a week, but when I hit the motoway doing 80mph it started overheating and all of a sudden the engine cut of so pulled over put water in and then it would not start. Took it home tried to turn car over again it would not start but I noticed water comming out the exhaust the never started and has been left on the drive the oil check stick is normal black and the oil cover is clean no white gunge so no sign of oil mix with water! But when the car cut out on the motoway I smelled fuel can anyone help as the only thing I can think off is anew engine which I cant afford. Thanks steve.