Marie Antoinette is credited with saying that "there's nothing new, only the things we've forgotten" or something close to that. In French, of course.
The point is that you already know what to do to feel better: eat clean, stop drinking, be nice and sleep deeply.
The knowing is the easy part. The doing is where it gets choppy.
Many resolutions will be made and broken over the next few weeks, leading to disappointment and despair. Don't get involved in that game. Start each day with the intention to care for yourself and those around you and do good work.
If you hit that mark more often than not, you win.
Never, ever, ever give up.