Final answer:
The speaker in Shakespeare's Sonnet 29 snaps out of his depressed state caused by self-doubt and despair, due to thoughts of a beloved person who brings him joy and happiness.
Step-by-step explanation:
The speaker in Shakespeare's Sonnet 29 does not stay in his depressed state because he experiences a shift in mindset caused by thoughts of a beloved person. In the first octave of the sonnet, the speaker expresses feelings of self-doubt and despair. However, in the volta (the turn) in line 9, the speaker changes his perspective and realizes that thinking about this person brings him joy and lifts him out of his depressing state. This change in perspective is further reinforced in the sestet, where the speaker contemplates the beauty and happiness this person brings to his life.