Agonised about coastal location (3,5)
I believe the answer is:
san diego
'coastal location' is the definition.
(city on Californian coast)
'agonised about' is the wordplay.
'about' indicates an anagram.
'agonised' with letters rearranged gives 'SAN DIEGO'.
(Other definitions for san diego that I've seen before include "Pacific port" , "California naval port" , "US city" , "Southern California naval base" , "City of S. California" .)