You don't want to actually stick your butt out by straightening your legs, riding at low angles (compared to a race alpine), there is a very large assymetric motion between toesides and heel sides. toesides, u naturally bend low, to increase edge angle, u still want to bend low heel sides, try using ur ankles as much as possible to tilt it high up, u must keep the same distance from your butt->board on both turns. don't let ur butt/center of mass get further away, or u will absolutely slip out in all but the most forgiving snow conditions.
Try sticking your butt out more. It will help you get lower, get more edge, and make it easier to get more weight on your front foot, which should give you the control/confidence to reduce your angle.