Answer:
I would say that the phrase from the passage that most helps create a tone of desperation is: "By heaven! I’ll make a ghost of him that lets me"
Step-by-step explanation:
This line shows the character's despair, show how he feels hopeless. He is asking, almost begging for his fate ("By heaven!"), he even makes a promise to whomever would help him to change his fate (I’ll make a ghost of him that lets me). This phrase shows desperation, he screams begging for help.