Possible Clues:

• ''__ my wit's end!''
• 'This is where ___'
• '___ your service!'
• '-- your disposal'
• ''___ your disposal'' (2 words)
• 'And while -- it...'
• "While ___ it ..."
• Sean Kingston's '___ War'
• '__ the end of my rope!'
• "__ the end of my rope!"