When you eat REALLY healthy, or less food in general as I have started fasting more regularly, you start feeling so good that when you binge on a lot of food, or sugar or eat something processed / artificial your energy almost immediately dives down. The contrast of high energy to low energy is so big the cause for the drop is undeniable. Even though I get off track occasionally, the massive contrast makes it easier for me to get back on track quickly and stay disciplined to do what makes me feel better.
This is why I suggest testing out the things that will raise your energy or cut the things that lower it, at least for a temporary period of time. At first you may not fully ‘understand’ why you are doing it or why its important, but when you feel better you get the substantial proof you need to stick with the changes. Its much easier to live disciplined when your mind has irrefutable proof of what is going to make you feel better.. not just logical understanding. Getting that proof requires changing up your habits sometimes.
USE FEELING AS YOUR GUIDE
Start with dropping the habits that make you feel the worst, and substitute with habits that make you feel the best. This will give you some serious contrast (strong feeling-based evidence) to make the habits stick!