The speaker of the poem is a man who has lost his beloved. And he is depressed and lonely.
He is hallucinating
Theories: 1) He's been drinking too much nepenthe. "Quaff, oh quaff this kind nepenthe" 2) The speaker has been napping and is very tired. "But the fact is I was napping"
befuddled.
Lol Raven Symone