The good news is although you went off, you probably didn't gain 5 actual pounds (probably water, etc. ). A pound = 3, 500 calories, so if you were way off track for 3 days, you would have had to eaten 17, 500 calories on top of what one eats in a single day just walk, breath, talk. It will take 2-4 days to get back in weight loss mode, but hang in there, and you'll be back on track!