Loneliness and anxiety after loss of heart (8)
I believe the answer is:
solitude
'loneliness' is the definition.
(synonyms)
'anxiety after loss of heart' is the wordplay.
'anxiety' becomes 'solicitude'.
'after loss of heart' means to remove the middle letters.
'solicitude' with its middle removed is 'SOLITUDE'.
'and' is the link.
(Other definitions for solitude that I've seen before include "Lack of company" , "Privacy" , "Lone condition" , "Absence of company" , "State of aloneness" .)