The quote is from the short story "The Birthmark" by Nathaniel Hawthorne and reflects the character Aylmer's disappointment and horror after achieving his desired goal.
The quote "I had desired it with an ardent fervor that far exceeded moderation; but now that I had finished, the beauty of the dream vanished, and breathless horror and disgust filled my heart" is from the short story "The Birthmark" by Nathaniel Hawthorne.
In the story, the character Aylmer has a dream about removing a birthmark from his wife's cheek. However, when he actually tries to remove it, he becomes horrified by the consequences. The quote reflects his disappointment after achieving what he desired.
This quote is a reflection of Aylmer's realization that his obsession with perfection has led to the destruction of beauty and happiness in his life.