Well, the best thing is just to get back to eating right. If you are producing morning ketones of 0.5-0.7 or higher (in morning fasted) then you are in nutritional ketosis. As for cheating, the longer you are in ketosis the less the cravings and hunger will be. This varies as it depends on how much leptin resistance you have. But just take note of how you feel after cheating and that should help you keep on track.