The Doctor pulled his arm roughly away from Jack. Not here, not in Jack's home city. This wasn't fair, starting this here. Why did the Doctor have to start it here? Things were going so well.

"At least then, I won't have to worry about you wanting to die," the Doctor snapped. "Because no matter how sorry you were this morning or how badly I want to move on from it, you still wanted to die. And only I could do it. And---Jack, I can't. I just can't."

He couldn't handle the thought of losing Jack. Of having to give him up, not like that. Maybe it was why he brought up Jack's mother, of what she might feel. Because, really, he wanted Jack to feel guilty. He wanted Jack to hurt, the way the Doctor was hurting.