Stay busy, give yourself a reward every hour or so (peace of candy, gum, etc.), and try to do things you enjoy. Also, log on here a lot, like as much as possible! We're here to help!
Is this your first day back in a quit? Because I know you were on your journey and today would be your 100 days and entry into the TDC. If you are still quit....welcome to the TDC! And if you are struggling today use what you've used to get to the TDC.
If you are starting again....let us know. If you are starting again what did you use to get to the number you were at and what was the cave? Figure that out so that you aren't in same place.