Two things that might help
What you lack is what we refer to as a "strong inside half". Don't worry, you're not alone. I spend a lot of time with instructors working on the same thing.
Here're a couple of things to try:
1) Tracer Turns - also called 90/10 turns. Simply this. Go skiing and keep 90% of the weight on the same ski - - turn after turn, always on the same ski - I'm not talking always on the inside/outside ski, rather, pick the right foot and put 90% of the weight there, turn after turn. When the "heavy" foot is the inside ski you will be forced to keep more weight on it. This works wonders and is easily practiced.
2) Do a series of traverses on the uphill ski
and uphill edge. Try to make a clean arc in the snow, no smearing. The cleaner the track the better you will be at this. This might take practice but will work wonders as well. A couple of things you will notice. First, you'll notice just how tall you need to be to be in balance. Second, you will find it hard to balance on the uphill ski until you keep your body moving forward. Try it with your uphill hand down by your side and then try it by keeping your uphill hand and arm reaching toward where you want to go. Here's how this progresses.
a) Then make the traverses a bit steeper until you can make a turn on the uphill foot while starting in a very steep traverse or even going down hill.
b) Then try this: about two-thirds of the way across a medium steep traverse gently put the downhill ski on the snow. You will feel the ski engage dramatically and the G-forces will increase and the turn will progress much more dramatically.
c) As you traverse across on the uphill foot try gently releasing the edge so you go straight across, rather than turn uphill, for only a second or two then re-engage the edge.
d) Get a partner and follow directly behind and leave your track in exactly the same line as he or she does.
The purpose of a strong inside half is to get the body well positioned for the next turn and to enlist the inside ski to carry some of the load. This directly relates to some of Bob Barnes's stuff about "come over here" where the body moves in the direction of the turn.
If you watched the short-track speed skaters in the Olympics you saw the necessity of a strong inside half. You saw them leading the turn by almost diving in. Even though they lifted the inside skate their body position was extremely strong.
Hope this helps.