This kind of a public self-reminder, but I just want everyone to remember that fitness is literally a journey. It may not feel like to today or tomorrow, hell not even next month, but you're going to see positive changes and improvement. I mean this in the least "hustle culture" way, but keep grinding everyone.
On the topic of your digestive tract “remembering” its last source of energy: I read years ago about the effect your diet has on your gut microbiome and the role it plays in setting your cravings. My understanding is that the type of food you eat encourages certain bacteria to grow in your gut which like those ingredients, and they release hormones and neurotransmitters that trigger your cravings for more of what the bacteria like. So there is a real physical change happening that creates and sustains these cravings based on your diet