on tenterhooks (?.)

• addled
• agitated
• all-overish
• anxious
• anxioused up
• apprehensive
• at a loss
• baffled
• bamboozled
• beat
• bothered
• buffaloed
• concerned
• confounded
• dazed
• disquieted
• disturbed
• fearful
• floored
• foreboding
• fuddled
• in a dilemma
• in a pucker
• in a stew
• in suspense
• keyed-up
• licked
• misgiving
• muddled
• mystified
• nervous
• nonplussed
• on edge
• on tiptoe
• overanxious
• overapprehensive
• perplexed
• perturbed
• puzzled
• quivering
• solicitous
• strained
• stuck
• stumped
• suspenseful
• taut
• tense
• thrown
• troubled
• uneasy
• with bated breath
• with muscles tense
• zealous