Clara walked out of her bedroom on the TARDIS and started to walk toward the kitchen. Clara stopped before she reached the end of what she liked to think of as the "bedroom hallway". She turned toward what had stopped her and faced the Doctor's bedroom door. She slowly walked up to the door and leaned her ear against it to listen. The Doctor's muffled sobs reached her ears. She listened for a second more before she placed her hand on the doorknob and opened the door.
As she stepped inside, she saw the Doctor curled up on his bed facing away from the door. The Doctor didn't show any sign that he heard Clara as she approached the bed. She tentatively sat down at the foot of his bed and silently watched him. He occasionally let out a quiet sob, but he mostly cried silently. After a few minutes, the Doctor sat up slightly and turned toward Clara. She felt like crying as she took in his tear soaked face. His eyes were slightly swollen and red rimmed and the tears that were still falling left silver tracks down his cheeks. She didn't say anything as he looked at her.
"2.47 billion," he whispered. "2.47 billion children and I forgot them. How could I forget them, Clara? How?"
"Trenzalore."
"That's no excuse," he spat, suddenly very angry at himself. "My death is not an excuse to forget 2.47 billion deaths that I caused. I caused them. Me. 2.47 billion lives that were never lived. And I forgot them," he screamed. "How could I forget them? 2.47 billion children, dead," he whispered. He seemed to deflate as all his anger left him and he started to sob like a lost child.
Clara quickly slid over to the Doctor. She hugged him close to her chest as he sobbed into her shoulder. Tears started to stream down her face as she leaned forward and kissed the top of his head.
"Shh. Doctor, you're wrong. Remember what you did? 2.47 billion children were saved. At least remember that. You saved 2.47 billion children," Clara whispered into his hair as she held him.
They sat like that for fifteen minutes as his tears subsided. He sat and held her close to him for a few minutes after his tears had dried. He pulled back and studied her face.
"Thank you. Clara..." He leaned forward and kissed her forehead. "...always exactly what I need," he whispered.