"You’re doing good. You’re so brave. We’ll be out soon", he murmured, trying to provide at least some comfort as he supported him.
"I know it hurts, love, but you’ll have to be strong for me now. Just a few more minutes. Your mum is waiting… And then you can sleep as long as you want."
Though that was not quite true. He couldnt let him sleep immediately, not before testing his blood for chemicals that would hurt him in that state. The timelord was too afraid his son wouldn’t wake up again.
Castiel looked at the Doctor, his eyes wide and eager. He finally started walking forward again, breathing hard. Each step was agony for him, and he was only going by sheer force of will at this point.
When they finally made it outside, he went straight to the TARDIS, leaning against the wood and pressing his forehead against it. His wings arched and curled around the box in a loose hug. He finally pulled away, turning to wait for the Doctor to open the door. By this point, he was too tired and worn out to even attempt to speak, and so he showed his love for his parents by curling a wing around both of them.