The speaker feels left over. "Like an epilogue to a revolution" is a striking way to say it: the big, loud event is finished, and what remains is a quiet afterword that nobody much needs to read. That image suggests someone who once belonged to something larger and now sits alone in its aftermath.
The middle stanza turns toward hope, though only a little. The "old rain" will become "new" again, as if the same grey weather could be seen differently if something changed. Nothing is promised, but the possibility is there.
The last stanza names what might change it: a kiss that could "light" the speaker's "grieved eyes." Grief is the word that stays with us, and it makes the loneliness feel like loss, not just solitude. The mood is hushed and sad, but not hopeless. The poem ends by longing for warmth and tenderness, and the wish feels all the more sincere for being so small and quiet.