The speaker begins Sonnet 137 by talking to "Love" as if it were a living being separate from himself—as if it were a god, in fact. The ancient Romans believed that Cupid (technically the god of Desire or Lust rather than Love) was a childlike god, sometimes depicted as blindfolded, who would make people fall in love with each other by shooting them with arrows. Sounds like a hoot at parties. Shakespeare uses the ancient god as a metaphor to represent that oh-so-troublesome emotion. One of the main benefits of describing Love as a god is that it lets Shakespeare present love as something foreign, something that comes at you from outside and turns your life upside down. It also conveys something about how powerful this emotion is. All of these ideas are present in Shakespeare’s poem, in which the speaker is furious at Love (the jerkface) for making him unable to tear himself away from a woman who is bad for him.
The speaker bears the sole blame for his own betrayal in love. Open your eyes, man!
Poor guy. Despite his anger, the speaker remains in love with his betrayer.