I'm switching back to Cas again. Happy Reading :)
The cracks were not healing. The pain was not subsiding. But it was getting easier somehow. After the 7th night, Castiel decided that wallowing in self pity as he was doing was selfish, and he wanted to useful again, even without the missing piece of himself. He emerged from his sanctuary dressed in one of Dean's shirts and a pair of jeans that were a few inches to long for him. Dean greeted him with a smile and a cry of, "Look who's finally up, sleepy head. Are those my jeans?" Sam was there as well, but his smile was notably more tired, and there were dark bags under his eyes. Castiel sat with them, assisted them with research and joined in occasionally with the mindless chatter.
The cracks were not healing, but they were indeed becoming easier to live with.