Two short lines tell the story of a breakup in its aftermath. The speaker has been given a diamond promise ring, a symbol of loyalty and a shared future, and then discovers "all the damage" the other person has done. The poem doesn't say what that damage is, and that gap makes it feel raw and private, as if the speaker can't bring themselves to list it.
The ring goes in the trash, and so do the roses. But the speaker keeps the thorns. That choice is the heart of the poem. The sweetness is gone, yet the pain is something to hold onto, because the alternative is worse: feeling "so damn numb." The mood is bitter and hollow, with anger underneath. Hurting, the speaker suggests, at least proves they are still alive. The blunt, unpolished language makes the confession feel honest rather than dramatic.