In the Raven poem which is a symbol of the narrators sadness and loss?

Pretty much every Word in the poem is melancholic! Start with "dreary" in first line, "weak and weary" in the second, the description of the bird as "grim, ungainly, ghastly, gaunt, and ominous," and the endless repetition of "nevermore." Add a few allusions to the Greek underworld ("the night's Plutonian shore"), and you have quite a bit of melancholy.