Its like someone was reading my mind when I read your post. I am only 25 days in to my first Whole 30, but your experience is exactly what I imagine happening to me if I'm not careful- it certainly reflects my relationship with sugar in general. I have a plan...
My plan is that once the Whole 30 is over, I am going to follow a strict paleo diet, and treat myself by purchasing a few really nice paleo cook books. And ONLY eat paleo treats when I have treats. I know I CAN"T handle the real stuff- milkshakes, gluten free cookies, etc... But will I make paleo pancakes with Almond flour, coconut flour, fresh fruit and coconut milk? Will I have coconut four biscuits with my bacon occasionally? YES!
My thinking is this- The reason that the whole 30 is working for me is that it is a food plan that I can live with- a "diet" with healthy rules. I can follow rules. I get wonky when I start doing things MY WAY. If I eat strict paleo treats (no cheating with sugar, dairy, etc), and that is all, then I have rules that I can live with. It wont blurr into McDonalds fries or a Sonic milk shake. That's against the rules. So maybe being a rule follower doesn't work for everyone- but to me it feels like a framework that I can live within. Once I cross the line into civilian eating habits... who knows?
So yeah, its just a theory, but we will soon see. I only have 5 days until its time to put it to the test.