Good-natured question showing self-doubt (7)
I believe the answer is:
amiable
'good-natured' is the definition.
('amiable' can be similar in meaning to 'good-natured')
I cannot understand how the remainder of the clue works.
(Other definitions for amiable that I've seen before include "'Friendly, pleasant and good-tempered (7)'" , "Friendly and good-natured (7)" , "'Affable, genial (7)'" , "Lovable, friendly" , "Charming" .)