Vauxhall Corsa overheating & water disappearing

After driving in the rain, about 5 miles with the Heater on full power, the engine started to overheat. When I stopped and checked the water bottle it was empty. Refilled and drove again and then the water was boiling making a popping sound like a kettle. Temperature went up high. Stopped and checked for leaks but couldnt see any, the water bottle was empty again. Exhaust also smokey not sure if connected. If anyone can help would most appreciate and any estimate of repairs that I will end up paying at garage! thanks very much,