Try to stop any extreme suffering (5)
I believe the answer is:
agony
'extreme suffering' is the definition.
(I've seen this in another clue)
'try to stop any' is the wordplay.
'try' becomes 'go' (both can mean an attempt).
'to stop' is an insertion indicator (stopping can mean blocking a gap).
'go' going inside 'any' is 'AGONY'.
(Other definitions for agony that I've seen before include "This aunt answers readers' questions" , "Torture" , "Great pain or suffering" , "woe" , "Excruciating pain" .)