The speaker keeps repeating the same line: they put everything they have into "this." The word stays vague, and that vagueness matters. We never learn whether "this" is a relationship, a job, a creative project, or something else. What we do learn is how much it costs. The speaker offers their soul, their sweat, "the whole of what I have," and the lines grow more desperate as the list builds.
Then the last line turns the poem around. The effort has not built anything. Instead there is "that hole we've created, abyss." The word "we" suggests the speaker isn't alone in this, so the poem may be about a shared effort, perhaps a relationship, that has gone empty. The mood is weary and bleak, with a quiet sense of futility. The short, repetitive lines feel like someone pouring and pouring into something that never fills, until the final word lands like a drop into darkness.