Does a person who has been afflicted in his testicles and become unable to procreate lose this world and the Hereafter, and live a life of misery and wretchedness?

What has afflicted you is by Allah's decree, and all of Allah's decrees for the believer are good. So be patient and seek reward, in fulfillment of His saying, the Most High: "No disaster strikes except by permission of Allah. And whoever believes in Allah - He will guide his heart." Allah decrees for the believer nothing but what is good for him, and He is more merciful to His servant than a mother to her child. As for sins, they are erased by repentance. Face your life with optimism, do not wish for death, continue your activities, strive in worship, and ask Allah for healing.