Sweetheart nearly got craving for what the diva has (8)
I believe the answer is:
egomania
'what the diva has' is the definition.
I can't tell whether this definition defines the answer.
'sweetheart nearly got craving' is the wordplay.
'sweetheart' becomes 'e' (the heart/centre of 'sweet').
'nearly' means to remove the last letter.
'craving' becomes 'mania' (I can't justify this - if you can you should believe this answer much more).
'got' with its final letter taken away is 'go'.
'e'+'go'+'mania'='EGOMANIA'
'for' is the link.
Can you help me to learn more?
(Other definitions for egomania that I've seen before include "Excessive pride" , "excessive conceit" , "Obsessive self-concern" , "obsession with self" , "Thing about me" .)