Since Jesus knew the future, it is unlikely He would have been afraid of death itself because He knew He would go to be with His Father in Heaven. But, more likely, He could have apprehended the pain (especially since His death would be one of the most painful deaths a human being could go through).  He probably felt the same kind of fears that we all feel when confronted with the thought of pain. We do know, according to John`s Gospel (John`s biography of Jesus), that Jesus sweat drops of blood in the Garden of Gethsemane before His death, and said: "Abba, Father, all things are possible to you. Please remove this cup from me. However, not what I desire, but what you desire."

Read more here in Mark`s biography of Jesus.