I would work on two point at a walk trot and canter to streghten those inner theighs...
Me personally I'm always in a half seat for Eq and a driving seat for Hunters and Jumpers...
Idk scratch that its hard to explain.
I would work at a two point at a walk trot canter and over poles and X's.
With time and practice you and your horse will start to click and you will just know.
I agree with MIEventer; stop thinking so much about the fence, this is causing you to jump for your horse which is why your ahead.
Pick an object over the jump and focus on that, let your horse do the jumping.