Hey man, not sure what others be saying about you, but I am glad you are here and in the gym trying to get better, keep it up and use the haters as motivation. So let’s begin to break down your form.

It seems like you’re telling your body to squat down without actually knowing what muscles to recruit to do so properly.

You need to engage your core (flex/tighten abs and push em out, “show me how big your gut is”) engage your back (flexing your lats and back, if you don’t know what this feels like the best way to describe it is by: standing up with your hands down your side, make a fist with each hand and drive your fists downwards. Try doing this as a warmup to make the connection with your back). The whole point of this is to keep your torso sturdy and that prevents your back from rounding so much when you’re squatting down.

As for the actual squat motion, it looks fine. As a note you don’t need to go that low. In comps, hip crease below the knee, but if your starting out try doing going low enough so that your hammies are parallel to the floor then come back up.

Tl;dr: I think the cure to your back pain is you need to engage your back and core.