"Is it possible to... not use it at all?" Sam asked. "Control it in a way that prevents it from doing anything?"
That was what he'd done. Gone completely cold turkey the moment it had all backfired-- too late to undo what he'd done, but that was usually how he did the important things. Too little, too late. "Or do you think that'll make it worse?"
He wished he had more ideas for her. The only other thing he could really offer her was to do the same thing that he did for Dean, act as someone who grounded her and pulled her back. But she didn't know him as well or care about him as deeply as his brother did, or vice versa. It would be harder for him to reach her when she went under.