Someone asked us recently after a fall for an incentive to restart his clean count to 90 days. Off the top of my head, I wrote him the following:
Our sages say two things:
1) "Repent a day before you die". Since we don't know if we will be alive tomorrow, we must always repent TODAY. Like a saying I once heard, Lehavdil: "Live each day as if it was your last. One day, you will be right". So if you knew you had only one day left to live, would you continue these self destructive behaviors?
2) And Chaza"l also say: "One must wait for Moshiach each day". If you knew Moshiach will be here tomorrow, would you not do your best to do Teshuvah NOW? A Jew is supposed to live with this Emunah - that he can come any day! And once Moshiach will be here, it will be too late. We will wish we could go back to the time when we had Nisyonos and could still show Hashem how much we wanted to do for him!
Both of these above are BIG incentives.
Take it one day at a time. Imagine today was your last day to live and/or the last day before Moshiach comes. You can make it through TODAY! Tell yourself that no matter what, just for TODAY I will stay clean.