I heard dr Peter atria say something along the lines of although electrolytes are important, we most likely store sodium pretty well in our bodies. Magnesium supplement while fasting is also important and shouldn’t be overlooked (I take magnesium glycinate and it’s said to be really good for anxiety).
Cortisol in the morning helps wake you up. As you can imagine, eating breakfast, which reduces cortisol, makes you essentially a little more tired, or lazier or more relaxed. However you want to put it, it ends up the same.
They say fasting increases cortisol levels but also protects you from stressful situations by making you prestressed and energetic. At the end of the day, they are paying you to do something. So if you take something to try and relax then you realized you have to do something to get paid or survive or whatever then your brain will just ramp up cortisol again until you’re active enough to do it.
So basically, just skip worrying about it and let the cortisol flow through you and get done what you have to do.