Sam M's "Heartless" is about the aftermath of being verbally attacked by someone close. The speaker accuses the other person of aiming for the sorest spot, and the quoted line, "You have nothing left then," shows how cruel the words were. The speaker then seems to take those words in, admitting they have nothing to live for and are a horrible friend and person. That shift from accusation to self-blame suggests how deeply the insults landed.
The poem also describes a pattern. The speaker cries "over and over" and keeps crawling back, which implies a cycle of hurt and forgiveness. The ending breaks it. "This time i won't crawl back" is a firm decision, and the last two lines, "I'm a pyramid / Not a grain of sand," turn it into an image of strength: solid, lasting, hard to knock down. The mood begins raw and painful, with short, blunt lines that feel like blows, and ends in defiant resolve.