General confusion:
* Confused
* Bewildered
* Perplexed
* Baffled
* Mystified
* Flustered
* Dazed
* Lost
* Unsettled
* Discombobulated
* In a daze
* At a loss
* Off balance
Spatial disorientation:
* Lost (literally)
* Displaced
* Misplaced
* Unmoored
* Off-kilter
Mental disorientation:
* Confused
* Foggy
* Dazed
* Groggy
* Disconnected
* Untethered
* Scattered
* Ungrounded
Emotional disorientation:
* Overwhelmed
* Shocked
* Stunned
* Traumatized
* Dissociated
* Out of touch with reality
Specific to a particular context:
* Motion sickness: nauseous, queasy, seasick, airsick
* Intoxication: drunk, tipsy, high, stoned
* Trauma: shell-shocked, traumatized, shaken
The best synonym to use will depend on the specific situation and the meaning you want to convey.