The speaker in the poem is a bereaved woman that might have been Emily Bronte herself. She is addressing, so to speak, her beloved a long time after his death. The poem is about attempting to "give up" or get past the person's death in order to live her life. She recognizes that his lost has stripped her life of its joy, and that she must get over it, but she cannot. There is more on this poem at this link:

http://www.enotes.com/remembrance-salem/remembrance