stupefied

as if struck dumb with astonishment and surprise

• “a circle of policement stood dumbfounded by her denial of having seen the accident”
• “the flabbergasted aldermen were speechless”
• “was thunderstruck by the news of his promotion”

in a state of mental numbness especially as resulting from shock

• “he had a dazed expression on his face”
• “lay semiconscious, stunned (or stupefied) by the blow”
• “was stupid from fatigue”