The title, "Autopoetics," hints that the poem is the speaker writing about their own making, so the "I" is partly a poet describing how they shape a self. The speaker says they suffer "auspiciously as a rose" from "unfinished pain." That's an odd, striking phrase: suffering is treated almost like a good omen, something that blooms. The pain isn't over, and it seems to feed the beauty rather than only harm it.
Then the speaker claims control. Having "made myself captain," they say they know who "he" is, as if the self they've built can be steered and understood. But the last lines cut against that confidence. "You see a man / dead of ordinary melancholy" suggests an outsider reads that same person as plain and sad, even lifeless.
The mood is wry, guarded, and a little lonely. The gap between how the speaker sees themselves and how others do is the heart of it.