Possible Clues:

• Terribly sure? No -- inside is very jittery
• Apprehensive rising star confused over lines
• Fidgety reverend shortly absorbed by commonsense in a jumpy state
• Twitchy
• With 19-Across, a worrywart
• Agitated - excitable
• Mostly very disturbed in mind?
• So to get over in the Sun makes one worried
• Around five, Nero is so jumpy with us
• Jumpy over spread in back of tabloid