Ran to protect fool, being worried (8)
I believe the answer is:
harassed
'being worried' is the definition.
(thesaurus)
'ran to protect fool' is the wordplay.
'ran' becomes 'hared' (haring is a kind of running**).
'to protect' indicates putting letters inside.
'fool' becomes 'ass' (ass is a kind of fool).
'hared' placed around 'ass' is 'HARASSED'.
(Other definitions for harassed that I've seen before include "Pestered; under strain" , "Distraught" , "Constantly tormented" , "Pestered continually" , "in a state of torment" .)