In my experience. there tends to be waves of challenging times that happen when we quit. They are most pronounced and most frequent in the first week or two, gradually (and I do mean gradually) lessening in intensity and frequency as the days/weeks go by. You can't rush the process you need to simply embrace it and tell yourself that your end goal (quitting for good) is the only thing that matters and do anything & everything you need to in order to ensure you reach your goal. There's no off/on switch to quitting. It's a process and takes considerable time to truely secure your life long quit.
If you stick with it no matter what; you'll make it!