The speaker describes a strange, almost surgical scene: wrapping a "rotten heart" in paper, the way you might bundle up scraps from a butcher's counter. The title, "Vivisectioned," suggests something cut open while still alive, and the poem feels like the aftermath of that kind of exposure. The heart has "gone quiet / like another ear," an odd image that makes it seem less like a beating organ and more like something that has stopped listening, or has nothing left to say.
What the speaker feels is hard to pin down, and that seems to be the point. Judging by the lines about being "out of my mind all morning" and "free of sleep," this is someone worn down, restless and unmoored. The last image, the "member falling out," is blunt and a little humiliating, suggesting a body that no longer feels under control.
The mood is bleak, raw and darkly matter-of-fact. The speaker doesn't wail; they just report, which makes the damage feel even starker.