Nahum speaks of the certainty of the destruction of Nineveh and the defeat of its king as if the king had suffered an incurable wound. (See: [[rc://en/ta/man/jit/figs-metaphor]])
The word "healing" can be translated with a verbal phrase. Alternate translation: "No one is able to heal your wounds" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
The writer either 1) speaks of wickedness as if it were a person who steps on other people while he goes from one place to another or 2) uses "wickedness" as a metonym for the people who commit it and "trodden" as a metaphor for committing wickedness. This rhetorical question emphasizes the negative answer that it anticipates. Alternate translation: "Your wickedness has continually trodden on everyone." or "There is no one to whom you have not continually done wickedness." (See: [[rc://en/ta/man/jit/figs-rquestion]])