Q: Overheating and battery draining.

Go look again under the hood and be sure that the serpentine belt is intact. It could be as simple as that since the belt drives the water pump and the alternator. As for the water, using water in the cooling system should not cause overheating by itself if the cooling system is in good condition, which yours does not seem to be. But of course, now you have no freeze up protection and the water will not perform as well at hot temperatures either. It sounds though like you might have a coolant leak and this will have to be remedied before you can drive the car. Contact YourMechanic to have a technician come out to your home or office to check out your overheating Cavalier and let you know what is the solution.