Disheartened (11)
(Other definitions for crestfallen that I've seen before include "Dejected after blow to pride" , "Dejected after a failure" , "Sad, disappointed" , "Feeling a blow to one's pride" , "Deflated" .)
'disheartened' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for demoralised that I've seen before include "despairing" , "Disheartened" , "Having lost confidence" .)