The speaker imagines themselves as a huge, dark body at the center of the universe, with stars circling and trembling in its pull. The image is a clever way of describing a person who takes too much. The speaker admits to greedy hands that reach for every point of light, and to a cold core that swallows love and life and leaves nothing behind.
Around this self-portrait, the universe carries on regardless. The sun still shines, the galaxies still shimmer, and everything keeps growing. That contrast makes the speaker feel small, and they ask to be reminded of their "colossal insignificance." Yet the ending is a confession rather than a cure. Even with billions of stars offering blessings, the speaker wants only one person, and wants to hold them close.
The mood is self-critical and longing at once. It sounds like someone who knows their need is excessive but cannot stop feeling it.