Romeo, who has become a prototype of the Romantic, emotional and melancholy lover, bemoans his being "out of favor while I am in love" (I,i, 90). The object of his love has "forsworn to love" and rejected him. Romeo's speech introduces the theme of opposites:
She [Rosaline] is too fair, too wise, wisely too fair,/To merit bliss by making me despair:/She hath forsworn to love, and in that vow/Do I live dead that live to tell it now. (I,i,187-190).
That he "was not at this fray" as Lady Montague mentions when she asks Benvolio about her son indicates Romeo's "in love with love" personality.
i think is attitude is unhappy because he is falling for juleit and he knows they are to way different people all along....