Can anyone please explicate and explain this poem ? Thanks.?

Some interpret it as Edgar being grief-stricken over people dying who were close to him. It's a dream within a dream, because the speaker is in such grief that he is emotionally removed from life and reality, and so life has become meaningless. In the beginning he might be kissing the forehead of someone he was close to who has passed away. So in effect the poem is about someone talking to a corpse, similar to Hamlet talking to the skull of his close childhood friend.