I wrote about this earlier, but it comes up again for me.
Fatigue is one of the common symptoms during a spiritual emergency. And there may be a few different reasons.
There is a burn out, perhaps following an initial awakening with strong energies running through the system.
There is an overwhelm due to strong energies, or wounds and trauma surfacing. Unexamined assumptions creates fear and a sense of overwhelm, this takes energy, and may lead to a sense of fatigue.
It’s part of the obscuration of the faculties (the personal will, intellect, morals etc.), it makes it so there is less energy to fuel the delusions, and this allows God (love, spirit, natural intelligence) more freedom to work on us as it wishes.