Wormtongue's Whispers
Edmund C.

From what I can glean from this debate, the main reason for Eowyn's depression has not been mentioned here yet.

She, like King Theoden, was subject to Wormtongue's lies. Though Gandalf used magic to heal the king, Eowyn did not receive that relief. True, the despair probably affected her to a lesser degree than Theoden, but the same hopeless outlook the King of Rohan bore was likewise apparent in Eowyn. I believe that this and the great strain of watching her dearly beloved uncle crumble before her eyes had a devastating effect.

Eowyn was a woman of action. I think, if I were in her position and I did not want to live anymore, I would want to die bravely in service to what I loved most. To her, this meant going to battle.

I am not sure if the healing and joy Eowyn found lay in finding her identity. The houses of healing, along with curing her wound might have cured her from Grima's spell. This, and the sympathy and unconditional friendship from Faramir, played a large role in Eowyn finding her happiness.