You can't overcome despair if you don't experience actual despair.
Then what do you call Alphinauids mental state after the collapse of the Crystal Braves? Hiding in Coerthas after being accused of regicide? What do you call Estinens grief at losing his entire family in the Dragon War? Thancreds eternal grief and self hate after failing Minfilia? Urianger's despair at the death of his dearest childhood friend? Lyse's grief over Papalymo's sacrifice?

Im starting to think you skip all the cutscenes and story.