I had cholestasis when I was pregnant with DD (she was born march this year). It's not much fun, I really feel for you going through it.
One doctor told me that a good way to ease the itch is to put mylanta on your skin (or any of the liquid antacids I guess). I think the difference between this and calamine lotion is that it feels a bit cooler when you apply it.
To cope with the itching, for the last few weeks of pregnancy I slept with my feet out of the blanket, a fan directed at my feet, and coated in either calamine or mylanta. I found that the itching was ok in the daytime and only really started up 1/2 hour after going to bed, so I tried napping in the day when I could.
Hope this helps a little.