Not 3, and struggling at night? (2,3,4)
I believe the answer is:
in the dark
'at night?' is the definition.
(thesaurus)
I don't understand the remainder of the clue.
(Other definitions for in the dark that I've seen before include "Told nothing" , "without being informed" , "Haviing no information - or light" , "Not knowing" , "overnight" .)