Ya, I agree with you there - it's a frustrating transition! The cool part is that once you know these things and potentially grieve the things you have to leave behind (yes, that's a real thing), you know that you're pretty safe that you're going to have an amazing experience at the Fall Fair because you didn't eat something that maybe your tummy was okay with but that gave you a headache or made you tired or grouchy... for instance... it's quite freeing but there can definitely be a grieving period as we move through this.
I also had quite a lot of trouble getting my "food freedom", what helped me a LOT was to find out that the food in itself wasn't the problem, I only used it to cope with my real problems, eating had become an addiction, to make me feel good when I felt helpless, sad, angry, bored…
If you feel like it might be your case, I can't recommend you enough the book The heart of addiction, from Lance M Dodes M.D. . Not only does it explain clearly what an addiction is, but it also gives you tools to fight it off on your own, with plenty of examples.
Although my brain still sends me the "I NEED FOOD" signal from time to time, now I'm better prepared to handle it, understand it, and that makes it way easier to ignore it.
Hope this will help some of you! Don't lose hope, and stay strong!