Counting everything, though utterly fatigued (3,2)
I believe the answer is:
all in
'fatigued' is the definition.
(thesaurus)
'counting everything though utterly' is the wordplay.
I cannot quite understand how this works, but
'everything' could be 'all' (all things) and 'all' is present in the answer.
The remaining letters 'in' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for all in that I've seen before include "Worn-out" , "Ready to drop" , "get tired?" , "Absolutely exhausted" , "Totally exhausted" .)