How to cut off emotions for a someone

I myself have never been able to truly cut off all emotions for someone. It's a trait I have, clinging to vestiges of the past and whatnot. However, recently I cut off a "friendship" with a girl who I cared about very deeply, but she was doing nothing but using me, even physically. So I told her she wasn't going to be a part of my life anymore. Since then I haven't talked to her or seen her, but if I did, I'm sure I would feel ghosts of those former emotions bubbling up from... wherever they bubble up from. And it would be unpleasant. But I'd bite my tongue and keep her at arm's length and probably be somewhat cold toward her, since I know of no other way of dealing with it. Oh, I'd be civil, but not warm.

Jam it back in, in the dark.