you could rename willpower with energy and get to a similar point, but at least for me, i feel willpower is what is driving me throughout the day. i don't see where the guilt should come from? if i run out of willpower or energy i need to rest and relax. every evening i reach that point. why should i feel guilty about that? there is nothing wrong with willpower running out. when i reach that point i know that i deserve a rest.

decision fatigue is another aspect of this. to many decisions to make and you are getting tired of that. i solve that by automating many things. (like watching tv or listening to books, i have them on a schedule, and the only time i need to make a decision is when i need to find something new to watch which happens every few months.