Q. I moved from an apt to a mobile home and one of my cats is terrified, he will not come out from under the bed. Going on for 3 days, w/o food or water
A. Give your cat time to adjust.. Animals can be quite fragile. Try feeding and watering your cat while she's under the bed. Maybe give her some wet food (more moisture) every day, add a little bit of water to it, put it under the bed for her to eat, toss some kitty treats under there, give her a bowl of water under the bed.. just make her comfortable under there and act like nothing is unusual. She will eventually come around.
When she does end up coming out from under the bed, don't make a big deal of it. Continue doing whatever it is you're doing, and act like she isn't even there. The more you make a big deal of things, the more she will make a big deal of them too, and it will end up making her more fearful.