Alternative to Willpower in Fighting Cravings
Some stuff for you to try:


Pace yourself, by letting cravings go in manageable steps (If everyone else deserves compassion, so do you in your practice of letting go)
Don't quit cold turkey, instead replace your habits with alternative
activitites (essentially anything related to the eightfold path, not
least meditation) 
Do Asubha bhavana (foulness meditation)
Study dhamma (disperses ignorance on this topic, and is also conducive to comprehension/panna and hope/saddha, as alternatives to viriya/willpower)
Ask your sangha (You already did)