I sure do hope you didn't fill your water heater with antifreeze... please tell us you really just shut off the input valve, put the heater on bypass, and only filled the water lines.
Then tell us you really removed the water heater plug and drained the water from it as best you could. When I do mine in the fall I put a small plastic line in and siphon out as much of the remaining water in the tank too.
But if you really did fill your heater with antifreeze, it will take quite a few full fills, drive around to shake it up, then pull the plug out and flush, repeat several times, before you don't notice the taste in your hot water.
There is much to learn... and loads of good information in the Truck Camper University at the start of this forum.
