@yosef87 It's great that you are actively seeking feedback on how to improve your form. I'm not a professional, but I've been through a lot with my squats, and I've learned a lot. Here's what I see, take it or leave it. I'm only going to focus on a couple of things, because I think you might be suffering from information overload.
A. Decide whether you want to do high bar or low bar. Right now, you are choosing high bar position with low bar squat mechanics. Based on your current style, I reccomend low bar squats, especially since it looks like you might have ankle mobility issues (which you should work on if you want a good squat anyways).
- Bar position: This is a decent illustration of what you should be doing with the bar depending on the squat style you choose.
B. Initiating the movement. I'm going to stick with explaining low bar squats, since that's what I recommend, but if you would rather do high bar squats I can do my best to explain that, too.
- Low bar squats are initiated by sitting back. What you have to be careful of here is not hyperextending your lumbar spine, and it looks like you're paying attention to that already. Your entire back--from your shoulders to your hips--should move as a single plane in order to sit back. It's more that you're breaking at the hips than it is pushing your butt back. Once you sit back, your spine should stay in roughly the same angle (in relation to the floor) until you're near the top of the lift.
C. Feet/knees. It looks like you've taken the advice of another redditor and turned your feet out, and that's good. I just want to reiterate that you should make sure you knees track in line with your toes.
D. Take a BIG BELLY BREATH before you drop into the squat. This will help you brace your core and keep your back from hyperextending. Make sure your upper back stays rigid and neutral as well.
I also recommend spending some time sitting down into the low squat position
without weight and focusing on achieving a neutral spine. Push your knees out with your elbows to help open your hips, and once you're sure you have a neutral spine, stretch your arms overhead and stand up. This should help you train your body into understanding how to squat correctly.
This has already gotten longer than I meant it to! Hopefully it has been helpful.
*Edit: formatting.
