Georgia,
My suggestion in terms of putting this into practice is for you to identify one baby-step change to make. You may well ear-mark what it is earlier, but remember you can only make your choice in the present time. When you get to the addictive desire (maybe you used Times and/or Plans to help you to identify it) you could consider “Working Through” and making a choice not to satisfy, as a trial to see what it’s like.
If or when you do that, if you then feel deprived, resentful and/or rebellious (which could happen because this mindset has been life-long) you remind yourself that nobody made you do this; it’s a choice you freely made and you can change your mind and eat those things/in those quantities any time in the future.
This how you train your brain to manage your addictive desire. You practice paying attention to the desire when it happens, and you link this to free choice.
Of course there is the fear you’ll only make bad choices (those you later regret) but there’s no way to overcome any fear other than by facing it. You can only develop trust – both in yourself and in the technique – by doing it.