I'm sorry, this is just dumb.
If you're trying to get someone to acclimatize to something that they have a phobia of (phobia may be too strong a word here, but hopefully you know what I mean), you give that person breaks. You don't just force them to be in the same room indefinitely until they get over it. That's like locking someone with agoraphobia out of the house until they get over it.
No wonder so many humans killed themselves or attacked the aliens. Just write it off as an irrational response due to extreme stress, probably compounded by sleep deprivation due to stress.