Need flying help

I recently purchased the Carenado King Air C90B and have great difficulty getting it in trim and holding it stable. No matter what I try the plane is all over the sky. I use the CH products Eclipse Yoke and Pro Pedals and have played with the axis settings to try to improve my flying to no avail. Are there any settings I might change, perhaps in the cfg file, that will improve the stability of the aircraft until I can learn to fly it better?