The speaker feels badly beaten down. In the first stanza he compares himself to something attacked by dogs and "worried to pieces," and the flat admission "I am a sorry man" sounds both pitiful and tired. He doesn't explain what has damaged him. We only get the feeling of being chewed up and left in scraps.
The second stanza moves to the shore. The image is a little hard to pin down, but the speaker seems to see himself as sand brought to a "moaning sea," as if he were being delivered to something much bigger than him. The sea arrives "to sign the new draft of my death," a striking, almost bureaucratic phrase that makes dying feel like paperwork being revised again and again. The title, "Spume," suggests the foam of the waves, something light and fleeting.
The mood is bleak and resigned, with a dark, dry humor running underneath. The speaker seems less panicked than worn out, quietly watching his own ending take shape.