Three short lines hold a whole tug-of-war. The speaker admits to a "pang of guilt," a small, sharp twinge of conscience, so they know something about their behavior isn't right. The title, "Self Blame," backs that up: the speaker is judging themselves before anyone else can.
But the second line pulls in the opposite direction. "But I can't stop" sounds like someone caught in a habit or compulsion. Then the poem corrects itself with a dash and a blunt "No, I don't want to." That small shift matters. The speaker first sounds helpless, then admits it isn't only that they can't stop, they don't want to.
The poem never says what the behavior is, so we only have the feeling to go on. The mood is quiet, honest, and a bit defiant, with a trace of weary self-awareness. The guilt is real, but the desire is stronger, and the speaker stops pretending otherwise.