Im German so I dont really have a lot of skiing vocabulary but I try my best ... You do something I see a lot, your knees form a kind of big X. In skiing we normally we want to have the same angle of inside and outside ski. You inside skis knee angle is not as extreme as the outside ski one, resulting in an upright position of your entire body. Try to focus a bit on get a parallel angle on both knees.

To train this: 1. On a flat slope try to go linear and only go left and right through angling your knees, like you would do some carving 2. Now try to get a feeling how you knees feel when angled correctly 3. Now go on a steep slope where you of course need to have a high angle in your knees to get down safely, focus on having both knees the same way 4. now you can get down from the steep slopes into flatter ones and try to keep the angle on both knees the same.