The only things I've found that help are time, video games (particularly puzzle games with out timers) when I'm trying to sleep, and not thinking about my abuser as much as possible which isn't always easy.

I think I use video games instead of disassociating the way you do but for the same purpose. If I'm not trying to sleep but a bad memory is locking up my life and panicking me, I'll play an RPG on my DS, like Rune Factory or the Legend of Zelda. The games have endings so I can escape into them when I need to without risking them eating my life the way online games like World of Warcraft would.