Exhaustion can make ordinary problems look permanent.

Tiredness does something specific to perception: it removes the sense that things could be otherwise. A problem that would look temporary on a good day looks structural, permanent, and characteristic of your whole life, and the certainty of that reading is part of the symptom.

When a situation feels hopeless late at night or at the end of a long stretch, delay the conclusion. Look at it again after sleep. It will not always improve, but you will be able to see it properly.