The speaker seems to be in a state of burning confusion. The first image, "white-hot and a black burn," puts mind and face in the same fire: one scorched by thought, the other marked by shame or damage. Looking for direction, the speaker finds only "money and a petticoat," a pair of images that suggests greed and desire, the two things that pull a person off course.
The second stanza turns darker and more bitter. The speaker admits to having "taken up with" death, calling it a dog and a "plenipotentiary," a word for an official with full power to act on someone's behalf. That odd mix of the lowly and the grand makes death feel both shabby and in charge. Then comes the sharp irony: "What a great profit I made. / How I cheated." The tone sounds like boasting, but it reads as self-mockery. The speaker has made a deal that looks like a gain and is really a loss. The mood is scorched, guilty, and sardonic.