Goethe survived his Werther phase; the character did not. This is the ultimate lesson of the novel. Art allows us to bleed safely. When Goethe wrote Werther, he put his own pistol down on the page.
However, modern readers often approach the text with a critical lens. We recognize that Werther is an unreliable narrator. He fetishizes Lotte to the point of erasing her humanity; she is a symbol, not a person. His "sorrow" is as much about narcissism as it is about love. Goethe himself later distanced himself from the novel, admitting that he exorcised his own suicidal ideations by writing them into a character. Genc Werther-in Acilari - Johann Goethe
To understand Werther, one must understand the Sturm und Drang (Storm and Stress) movement. Goethe was rebelling against the cold logic of the Enlightenment. Where the Age of Reason demanded control, Goethe screamed for emotion. Werther represents the ultimate Romantic martyr: a man who would rather feel too much and die, than feel nothing and live. Goethe survived his Werther phase; the character did not