The speaker describes sadness as an endless, raging sea, and the whole poem stays inside that one image. They feel like they are drowning, with no sense of which way is up or forward, and nobody around to pull them out. The question "How could they just leave me here?" suggests the speaker feels abandoned, and that hurt seems to sit alongside the fear.
The mood is panicky and claustrophobic. Short lines and broken phrasing mimic gasping for air, and the list "Surrounded, trapped, scared" piles the feelings on top of each other. There is a thin thread of hope in the middle, when the speaker imagines that "someone will come," but it is only a "maybe," and the poem soon slips back into dread. The ending is the darkest part. The "monster" that has swallowed the speaker's memories seems to stand for sadness itself, and the closing question, "Am I next?", leaves the poem on fear rather than relief.