Annoyed when struggling to find pain reliever (7)
I believe the answer is:
anodyne
'pain reliever' is the definition.
(I've seen this before)
'annoyed when struggling' is the wordplay.
'when struggling' indicates anagramming the letters (I've seen this in other clues).
'annoyed' is an anagram of 'ANODYNE'.
'to find' acts as a link.
(Other definitions for anodyne that I've seen before include "Annoyed, being pain reliever" , "Unlikely to cause offence - rather dull" , "Harmless, bland" , "Innocent" , "A drug that relieves pain" .)