It'll take alot of practice and repetative work. Just keep repeating the fence over and over. Remember, you aren't going to be AT the verticle, you are going to smidge your upper body just ahead enough to be slightly infront of the verticle - like how the girls upper body is in the first vid I showed you.
AND STOP looking at the fence, because I know you are *wink*
What I would highly suggest, is have someone put you on a lunge line if you can, if not on Zeus, on a more trustworthy mount - where you can ride with no reins, and learn to feel your horses rhythm.
I would - if I were your coach - have you do this for a good while. I would have you act like you are going to go over a fence, while there is no fence there, but have you hover over his center of gravity for a good 5 strides at the trot and at the canter, then release.
Then I would have you go over cavaletti's. No reins, and FORCE you to learn to stay with your horses movement and over his center of gravity. You have to figure it out on your own - you have to beable to FEEL it for yourself.
Lunge Lining with no reins, is oober, oooober benefitial for ANY rider out there. Even GP Jumpers do this to put their riding back into check.
Ask around, and see if anyone at your barn would be willing to help you for an hour here and there. You'd be absolutely amazed at what you figure out as to where you should be while in the saddle *seat, legs, upper body* and that will help you out immensely!
Watch this young lady do it with no reins. Get to 4:45 and watch her upper body and hips flex as she goes over the grid. That is what you need to work on, while on the lunge with no reins.
Now - NOT a whole grid, but 1 cavaletti at a time.
You get the idea...