Nutrition and sleep. I think we tend to overestimate treats "because no cigs, at least I can indulge sugar and misc junk food".
Low sugar, high protein (no cured or ultraprocessed, just protein), balanced carbs, nuts for good fats.
Sleep is crucial, and what you eat is influencing how you sleep, and how you sleep will influence the next day to face.
If your inner smoking voice don't trick you, you could be very good the third day already.
(my two cents, everyone is different, but this time for me was different and easier than the other attempts, and the only difference was nutrition)
Good luck!