I'm having to put water where the antifreeze belongs.

if your oil looks milky then it is leaking internaly if not try to spot leak underneath car or inside car maybe heater core hope its easy fix also might be thermostat stuck closed or waterpump not working

I don't know anything about cars....that happened to me once and at first they thought I had a hairline crack in my radiator but it turned out to be the water pump.

TOW to a shop (prefferably find one with VW/german car experience). They can pressure test system and find the cause and location of coolant loss. DO NOT add plain water and run it!!!!! You WILL cook it!