Try to change the Pedals to No Spring FFB.
And then, use curvature 0 and 90 on Y curvature. The solution is not set curves, because they get very sluggish at the start of input, and then they suddenly increase. The important thing is to reduce the rate at which movement occurs.
Then start changing curvature to your liking. Mine is set at 20 and 90 Y curvature.
And use collective very, very slowly. The torque onset on the Apache is much greater than other DCS helos.
RodBorza's post in Yaw axis oversensitive ? was marked as the answer