In your bump skiing, you are almost always aft on the ski. Until you learn how to get over the center of the ski, you are not going to be able to do much. From an aft position, or a forward one for that matter, your ability to tip the skis from the feet up is very limited. So, the first thing you need to learn is how to find and stay in the center of the ski. You are not going to be successful in absorbing terrain, pivoting, or making tactical choices until you've got ownership of that skill.
How to find a centered stance? First, try standing still and try to hop. Do the tip and tail come off of the ground and land at the same time? If not, you are not in a centered stance. Feel where the pressure is on the sole of your foot. Lean all the way forward on the front of the boot. Lean all the way aft on the boot. Where do you feel the pressure on the bottom of your foot? In a centered stance, you should feel the pressure slightly in front of your heel. Not on the ball of the foot, or totally on the heel, but slightly in front of the heel.
Try making some gentle turns on groomed snow. March as you make your turn. If you are balanced on the center of the ski, you will be able to march, alternately picking up the inside and then the outside ski.
Try making smeared turns. Where do you feel the ski turning? It should feel like it is turning under the center, or the heel, of your foot.
Once you are in a centered position, and able to maintain it while skiing, then you will be in a place to start to work on the rest of the package. Until then, your stance will limit your ability to make progress.
Mike