Regret is a short, bare confession about a love the speaker ruined. The opening question, "How could I be content?", sets up a restless person who never seems satisfied. The next lines are blunt and quick: "I chased you, / I caught you." Then comes the turn. Once the speaker had what they wanted, they left.
The middle of the poem softens. The speaker asks, "Do you regret the time we spent?", which sounds like a real worry, as if they need to know whether any of it mattered. The other person is remembered as "soft, tender," while the speaker's own desire is "fire." That fire grows until it burns the other person up. The final line is the cruelest: nothing was left that the speaker loved.
The mood is cold and guilty. The short lines feel like someone admitting fault without making excuses. The speaker seems to know they destroyed the very thing they were after, and the regret in the title comes through in the plain, stripped-down wording.