Maybe film a couple attempts with the camera setup across from the rollin to see if you have a little more room on that backside turn than you think. I see you have to avoid the rollin section, but maybe you can start that turn a little closer to it to give yourself more time/space to turn through that corner.

You are worried about falling and drop your arms to the ground. Look and point where you want to go

Your body looks very tense and hunched over.Try lifting the elbows and straightening your back and you should find it easier to move. 

I'm having the same issues but I think it's a speed issue. Centrifugal Forces will only work and allow you to drop your head if you are travelling at speed. Try leaning your push bike on a turn when you're going slow and you're gonna kiss concrete. Speed is your friend on this occasion me thinks 🤔