The speaker is stuck at a desk, going through papers, and feeling completely adrift. The opening images show a mind that can't focus: a gaze that is "lost," then compared to a "lost foot" on a road that is "like a held tongue," a silent, stalled path. Nothing moves, and nothing gets said.
The middle of the poem makes the problem plain. Sit in one place long enough and you become "a stranger to the light," cut off from the outside world and maybe from yourself. From there the mood turns from numbness to anger. The speaker wants a "broadside," a forceful attack in words, "ready to burn down Monday," meaning the whole grinding week ahead. The final demand is for a swear word, spelled out letter by letter, "born in a whip." The poem suggests that one sharp, rude, honest outburst might break the dullness. The mood is bleak and frustrated, with a spark of rebellion at the end.