This is so breathtakingly beautiful... you've summed up just about every thought I've ever had about how Arwen and Aragorn might have thought and felt and lived as a married couple.  The nightmares, the need for darkness to share his painful secret--that bit was wrenching to imagine yet still felt very much like Aragorn, for you still have him whole, which is something many fic authors don't manage when they create painful pasts that have scarred him.  And the repeating of him saying her name was a stroke of genius.  I loved how it tied the stream-of-consciousness together.   Really, really a wonderful story.