confused, puzzled, perplexed, baffled, lost, amazed, astonished, thunderstruck, shocked, muddled, upset, dismayed, dazed, giddy, dizzy, reeling, vertiginous, misled, addled, mystified, uncertain, surprised, disconcerted, taken aback, nonplused, aghast, put out of countenance, adrift, at sea, off the track, awed, stupefied, astounded, struck speechless, agog, agape, breathless, befuddled, bemused, startled, struck dumb, dumbfounded, dazzled, stunned, confounded, staggered, awe-struck, flabbergasted, flustered, rattled, all balled up*, in a dither*, lost in the fog*, bowled over*, euchred*, fazed*, come unstuck*, at a loss*, all hot and bothered*, going around in circles*, in a stew*, up in the air*, stumped*, punchdrunk*.

Antonyms self-possessed, rational*, cool.