Three short images add up to one weary, angry mood. In the first, the speaker is awake at night, head aching from bad news about hatred in the world. "Midnight in my head" makes the darkness feel inner as well as outside, as if the news has turned the mind itself into night.
The second image is odd and a little comic: a moth, set against an oak, seems to be "beaten by the green afternoon." A small, fragile creature is overwhelmed by the sheer size and brightness of the living world around it. It is easy to read the moth as the speaker, a night creature worn down by a world that feels too big to face.
The last lines turn outward. The speaker curses "the wind / of our nothing-but-money lie," blaming a society that values only profit. The title, "Resistor," suggests the poem itself is a small act of pushing back, even if all it can do is curse. The mood is tired, bitter, and quietly defiant.