The problem with will power is that most of us, a super majority in fact, have little idea how will power actually works.
You have exhibited will power from your first Dragon Slaying post. How do I know this? You have the foundation well in place. The foundation is refusing to give up.
Quitting and then going back to smoking isn't giving up, it's just part of the battle.
My story is quite typical, though many might deny it and attribute their success to other things. I started with intent. I clarified that intent by study. I knew exactly those things that were the reason for my intention to using tobacco. I might add or subtract or do some priority shifting but in the end nothing much changed. I had my reasons and they were the basis of my intention.
I think I progressed immensely though when I added just one more thing to my list of reasons and gave it to my "intent."
I envisioned the day of my death. And I envisioned what I would be doing if I had not as yet quit smoking. Yes, I would still be tasking myself with my intent.
I laughed over that quite a lot, and it made clear to me that it would be silly to be on my death bed still battling smoking.
I gave up plans, by the way. I gave up helpers of all kinds. And I focused on my intent.
I smoked Kent hardpack, 'cause I was a "cowboy." One day I was crossing my living room about to go outdoors and work on something. I pulled the pack from my pocket and even took hold of the pullstripe and stopped and said to myself, outloud I think, "Smoke one if you really want one." And I didn't. Not right then anyway.
I threw the pack down unopened on the coffee table in front of the couch. Later that day I stopped there again and looked at the pack, and said the same thing. "Smoke one if you want one." "You have to really want one." "It's okay, take it and smoke it if you REALLY want it."
This went on for many days, and weeks, and I never did pick up that pack. It was there a couple of years later, being dusted and put back occasionally.
What I missed, but only understood later was that smoking is a ritual (that part I knew), and I had replaced one ritual with another just as powerful and satisfying (that I didn't know for a time).
By now you are establishing your own ritual. I'll be curious to learn what the last piece of it is, one day.
In fact you have about half the ritual done already because quitting is a process of decision making just as I've described above and that is a ritual for us all.
You are preparing for that last step, the little addition to the ritual that will be there for you always. Possibly not quite ready yet, but very close I think.