Commenting on lines 45-52 in her book The Romantic Mother: Narcissistic Patterns in Romantic Poetry, Barbara Schapiro points out that the poet's love for Emily is also "revealed as a love of self" which "is inevitably doomed to dissolution and failure" (6).
In her book, Schapiro's claim is that the image of the woman--either "an ideal goddess or a serpentine vampire, a deserted woman, or, more frequently, as the ever-maternal Nature"--is a central figure for the romantic poets (ix).
Schapiro reasons that the emergence of the "wounded narcissist" in Romantic poetry
suggests that the Romantics were open to the deeper layers of the psyche and in touch with those earliest, formative stages of personality development in which external reality and one's own identity are first being realized. The poetry of the Romantics not only opens and explores new psychic territory but the best of it portrays the struggle of the ego to resolve its internal conflicts and ambivalences, to make contact with reality, and to establish mature object relations. (xii)
I would agree with Schapiro. This passage reminds me of Keats's measured complement of Wordsworth in his "Chamber of Maiden-Thought" letter to J. H. Reynolds. Freud's essay "On Narcissism" in General Psychological Theory should be helpful. For more information on psychoanalytic theory, check out Dino Felluga's Guide to Literary and Critical Theory.
Schapiro, Barbara. The Romantic Mother: Narcissistic Patterns in Romantic Poetry. Baltimore : Johns Hopkins UP, 1983.