I noticed this on my sorcerer in the late 40s/early 50s too. Then it all seemed to change around 53 for some reason. I started killing things too quickly for much damage to get through, and khem wasn't falling down every fight. Maybe it was just when I got used to the changes, not sure. But it does get better as a sorcerer, now at 60 I'm having all kinds of fun, and rarely lose khem (sometimes I get a little -too- ambitious). Keep grinding it out!
You get some gear during forged alliances quest line to help make up any deficit you might have at 55, I know I did, and the bump in gear level made a huge difference as well.