k, first of all... your squat is great, there's nothing wrong with you.
You have legs right to your chin and you're going ass to tea kettle. when you hit the hole, you're pretty upright, but when you come up your glutes and hamstrings completely take over causing you to bendover. The low bar really doesn't help.
To be more upright you're going to have to push your knees way way forward, and not sit back, but rather sit between your legs. you're going to have to increase your front squat like crazy, as your hams/glutes are taking over, so I'd start front squatting as your main movement, and back squat after that. Also, you'll have to switch to highbar.
Watch the girl before you, see how far her knees for forward? she has similar proportions to you, so use that as a guideline.
Also, watch the girl at 1:46:44... AJ Facendi... she's amazing and a really great lifter. She's from Edmonton, so add her on facebook and ask to train with her. You both have the same proportions, see how she's not going all the way down, but rather optimal depth? notice that she wears weightlifting shoes, this will also help a ton, and is a requirement, get the new Nikes, they have a big heel and you need it.
So to recap:
go deep, but not crazy deep.
push your knees way forward, and sit between your legs. you may need to stretch your calves and ankles.
go highbar, or at the least regular bar, ditch lowbar, it's not for you.
get weightlifting shoes immediately, at the least squat with a plate under your heels.
Make friends with AJ and train with her.
use front squats as your main move for a while to develop the flexibility and technique you'll need to make this change.
if you're still freaked about butt winking, do some dynamic hamstring stretches, such as a rollover into v sit, and hip swings before you squat, pelvic rounding is caused by tight hamstrings. Though in your case, it's hard to tell as you're going so deep.
That's all, you're a good squatter, continuing to think there's something wrong with you will just make it so, I officially give you permission to chill.
PM if you have any questions at all, and pay no attention to someone who prescribes good mornings or an exercise to fix your form, exercises don't fix form, changing form fixes form.
Best of luck.