BERLIN (AFP) - Germany's Nobel literature laureate Guenter Grass admitted here he had experienced a difficult few weeks since confessing he had been a member of the notorious Waffen SS in World War II. "It has not been easy for me recently, but I am still standing on my own two feet and will continue to open my mouth," Grass said. Grass was speaking at the first public reading of his new autobiography "Peeling Onions" in which he made the admission which stunned Germany. Grass, 78, has faced severe criticism for waiting more than 60 years to make the confession, especially because he has acted as a moral compass for many of Germany's post-World War II generation, urging them to face up to their past. Grass said that at the age of 17 he was conscripted into the elite corps responsible for some of the worst Nazi atrocities.