It's kind of common knowledge that Sugar (amongst other things) is addictive but there is an interesting article on the Independents Website from last month that attempts to explain some of the drivers and science behind it.
Lots of people "Beat themselves up" for being greedy but could it be, that genetically you're more susceptible to addiction and are struggling against what are essentially primeval urges.
“If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.” ― Sun Tzu, The Art of War