What to do when the BS comes up?


I feel like I understand the food and planning my food part (although I do think having the set restrictions of no flour sugar, set meals alone will take a lot of the “should I eat this” “should I not” out of it just that alone). But I guess I’m
Curious how to actually just allow all the feelings and urges that come up and more how to work on the mental aspect. I’ve heard your Model explanation and urges so I have an idea of them. Usually when I get urges or that uncomfortable “I want sugar NOOOWWW!!” Feeling comes up it’s so uncomfortable that I just give in and say I can’t do it or I’ll start over tomorrow. I know that’s not helping my cause logically but when it comes down to brass tacks I give in eat all the sugar and then say I’ll start over. I guess I’m wondering if I need to do a model in this situation? Or am I not allowing the urge correctly? I’m not even sure what my model would be….would my circumstance be wanting sugar? Id imagine my thought might be something like “this sucks and is horrible” and this is where my crux is….changing my thought to something else? Thank you!!