Sohrab had been through a lot in his life from losing his parents and way of life to being sexually abused and used by the Taliban. He said he had felt "dirty" and didn't think his father would be proud of him in that state or want to claim him as his son. Even though those events affected him, Sohrab felt like it was the last straw when Amir told him he may have to go back to the orphanage for a little while during the adoption process. This is ultimately what triggered him to attempt suicide. A little after this, Sohrab doesn't speak again, showing how mentally affected he's been by all of the trauma he's faced. The reader doesn't get much entail on the future, but can only assume that Sohrab will struggle with the pain of his past similar to Amir.