We started the poem with sad leaves under a sad sky, described with the words "ashen," "sober," "crisped," and "sere." Now that image comes back, but this time the sadness has spread to the speaker's own heart. We think this line really shows how horrifying it was for him to realize where he was, to remember the loss of Ulalume. If this poem started out sad, things have only gotten worse. That's trademark Poe. He doesn't want us to simply recognize the sadness, but to soak in it for a while, to almost enjoy it.