She rubbed his back trying to both analyze what she had seen and lock it away in her own mind. It was painful enough to have the memory so briefly she couldn't imagine having them for as long as he had or even living them herself. She was strong sure but not nearly strong enough to do what he did. He was the only one who could have ended it.
"I'm here now." she whispered. "You aren't alone anymore." she doubted he could hear her really but she had said it. There wasn't anything else she could say. Saying she was sorry or that it would be ok would be lies. There was no changing what had happened. As much as she couldn't say it she was sorry the Doctor had to experience what he had. She had to be there for him. It was the only thing she could do for him.