I don't know if I can express this in a way that everyone will understand but I'll try. It is not the work at hand that overwhelms you. It is the mental list of crap you got to do someday that makes you tired.
Now that doesn't mean you shouldn't plan ahead a little. You need to have materials on hand to work at something without unnecessary delays. You need to dig the hole before you mix the concrete. Planning is one thing. Being overwhelmed by the sheer size of the "to do list" will make you tired before you even get started!
Looking ahead is great if you are walking and don't want ran over by a car or something. I drive myself about half crazy thinking about what I got to do next week! Those of you who know me pretty well knows I can't really afford to get any more crazy! ha ha ha ha
I am trying to teach myself to deal with what's in front of me. Slowly but surely one thing will get done and then another and at the end of the day you can look and say OK! Good productive day!
Maybe it is my age catching up with me. I don't want to think about next month or next year. I want to concentrate on maybe now-to-bedtime! If I wake up alive tomorrow, I'll do the same thing again..
Does anyone of you share this problem?