Get those knees out! Really try to rotate your hips "open" push your knees out, and sit down between them.
Goblet squats, with a dumbbell held up in front of you can help with this. Squat down, deep. Use your elbows to push out, against your thighs, and get comfortable in the bottom position.
The crossed arm, or body-builder, or genie style rack my help you keep your elbows up and help keep your back upright. Maybe give it a try.
Does your gym have a cambered bar? These are great for teaching you to drive your shoulders back into the bar. And if you have shoulder issues, it can be easier to get tension in your back with your arms down lower.