"The writer's shortness of breath became more and more distressing as he rose"

The quote is referring to the physical and psychological distress of the writer as he rises. It suggests that the author is having a hard time to breathe, and that this problem is increasing as he rises. This might be interpreted as a metaphor for the author's emotional state, as he is struggling to manage the situation he is in. It might likewise be interpreted as a physical symptom of stress and anxiety or worry, as the author is feeling overwhelmed and unable to cope. The quote might also be analyzed as a sign of physical exhaustion, as the writer is having a hard time to stay up to date with the needs of his work. Whatever the cause, the quote recommends that the author is feeling overwhelmed and is struggling to deal with the situation he is in.