Speaking directly to the people they care about, the speaker makes a wish under a starless night sky, looking at the moon, the "lonely rock reflecting light." The image fits the mood: dark and isolated, but with a small glow still there. The speaker quickly heads off a fear readers might have, saying this is not a goodbye letter and that killing themselves wouldn't help them or anyone else.
The final stanza is the heart of it. The speaker asks whoever is reading to look toward the future, and admits that this doesn't have to be done in a cheerful way. The ask is modest: just live a little longer. That honesty makes the poem feel believable rather than preachy. It doesn't promise that things will be bright, only that continuing matters. The tone is tired and gentle, with a thread of stubborn hope running through it. The speaker seems to be talking to others and to themselves at once.