Fairy wrasses do not typically do well solo. They are best kept in "harems" with one male and several females. That and added to it you have a pseudochromis which is not a good mix at all. Pseudo's will terrorize most wrasses large or small. What species is the pseudo?
If the wrasse does not show signs of coming around soon, it should be returned.
FWIW, your tank is quite well stocked before it's addition.
Cheers
Steve