I'm kinda conflicted on this whole thing about Kyousuke. Because while what Taka and Karifean say makes sense, while I was reading I thought what Pepe was thinking.
So we can agree he's tired, yes? Tired from supporting the world with increasing less help from the girls as they're regrets disappear. And tired from traveling back and forth between the two worlds, experiencing the pain of being almost dead over and over again.
So is he actually dejected and hopeless? Well, he certainly has reason to be. His plan failed. Instead of becoming stronger, Riki and Rin fell into darkness, and Rin was now stuck there. Kengo doesnt trust him, Masato is acting as he always promised to act, Rin's mental state is shot, and Riki (at first) still can't remember any of it. The Little Busters are dead. The most prominent evidence of the whole thing NOT being his plan is his comment that "He'd never seen the gears of this world so messed up before."
But I'd say dejected, yes. Hopeless, no. Because he continues to try to fix everything, by himself yet again. As already mentioned, he kept going back to "the World Where Something Happened," trying to fix, to change the circumstances, to contribute to Riki and Rin's survival. But in the Fake World too. He causes Masato to go crazy. He tries to rebuild the Little Busters.
The only thing I'm not sure of is whether he was purposefully trying to imitate the past Riki, and turn Riki into the past himself; or if that was the ironic effect of Riki becoming stronger, while he continued to be alone, stuck in the darkness.