He may have some testicular damage which can result in lowers testosterone levels and a decreased sex drive he needs to see a doctor.
He may have Epididymitis, Varicocele, Hydrocele, or Spermatocele. Almost all can cause similar symptoms to what you are describing. Google it. None are deadly and most are reversible. The sooner the better. It may be the cause of your infertility considering you have had yourself checked. He needs to do a testicular self exam to rule out cancer. Google it.