Can't see your stance width from this angle but here is what I see based on this view
Your form problems stem from two things:
1.) you are attempting to keep your back too vertical. Don't be afraid to lean over more.
2.) do you see your knees caving as you get deep? This is a function of staying too upright and not shoving your knees out. The knees come forward and out and the hips go back simultaneously. You need to get out of your knees and engage your posterior chain. This could be a mobility/flexibility issue and its one you need to work on.
3.) I see you have a mirror in front of you. Do your best to not look at the mirror. Fix your eyes on a point on the ground and keep them there the entire set.
4.) get rid of the pause at the bottom. You should be bouncing out of the whole. Use the stretch reflex. This should be smooth. Your pause is hurting you.
5. Cut off the depth a bit. You don't need to go quite so deep. My knees are hurting me just watching this video.
6. Get some lifting shoes, those squishy basketball shoes r very unstable
7. Lack of hip drive. You are lifting with your chest and not using your hips
Check out some form videos coached by coach Rippettoe. They are invaluable. Keep at it, you will get there eventually.
He's doing high bar squats. The cues I bolded in your post apply to low bar (which is what Rip coaches), but not so much to high bar squats.
In low bar, you have to lean over forward because that's the only way to keep the bar path perpendicular over the middle of the foot, and also because you have to keep your shins as vertical as possible while sticking your butt out at the bottom to keep maximum hamstring tension. This is also the reason you shouldn't really go more than a couple inches below parallel in a low bar squat; going deeper results in a loss of hamstring tension.
But in high bar, the knees travel forward over the middle of the foot quite a bit, and thus the back must remain fairly vertical to keep the bar path perpendicular. And as a result, there's much less hip drive, because the angle is mechanically less favorable for it, hence the cue for chest drive instead. This is due to the acuteness of the knee angle in front and high bar squats, resulting in a slackening of the hamstrings. Because of this shortened state, the hamstrings cannot contract further at the bottom to help drive the hips up. High bar squats are much more quadracips dominant.
There's basically a continuum regarding the back angle in squats, going from Front squat (where the back is at a 90° angle) to the high bar squat, to the low bar squat:
This continuum also correlates to the distance the knees travel forward over the foot, as well as hamstrings recruitment (significant in the low bar squat; almost non-existent in the front squat), and correlates inversely to quadriceps recruitment.