The speaker begins with a quiet, heavy feeling, "a white weight," and sets it beside something far worse: a war that others are living through. That contrast seems to leave them somewhat ashamed of their own pain, or at least unsure what to do with it. The "one-inch rose" is a tiny, fragile image of grief, something delicate and easy to overlook.
Then the poem turns strange. The speaker goes to "the park of my enemies," a place that sounds peaceful but belongs to the people they are angry at. They say they go there "to guard my addiction / to the cross and the sore." The title helps here: the speaker seems hooked on anger and suffering, nursing a wound rather than letting it heal. Judging by the wording, the "cross" suggests sacrifice or martyrdom, while the "sore" is simply an injury kept raw.
The mood is bitter, restless and self-aware, with a hint of grim honesty about clinging to pain.