2000 Ford Mustang Losing coolant, white smoke

I had a coolant leak between the radiator upper hose and the radiator. I changed the the hose, but still leaking then i changed the radiator and a new hose clamp but it still leaking, so i bought a screw hose clamp.It stopped leaking but yesterday i checked my coolant tank and it was almost empty i drove the car for a while and it wasnt leaking but there was a white smoke coming out the exhaust. My catalytic converter has a small hole and im not sure if thats why the white smoke is coming out the exhaust but I still losing coolant.