Here is my 2 cents. Your weight is on the backside of your body. Try leaning forward more. It will help the weight transfer from your reach back. It will be difficult to adjust balance issue but just practice it. Also you don't twist your foot correctly. It should be more on the center of your foot and you twist your foot the same time as your body. You have a delay in the twisting motion and you are on your toes. Try pulling back as far as you can and act like pulling on a rope for one arm tug-a-war and then drive your elbow as far as you can. This will help keep the disc close to your body and generate more speed and spin. But if I have said anything wrong someone else can comment and correct me.
In the Grip-L
Challenger | Meteor | Nebula | M1 | Eagle L | Eagle X | Firebird | Sidewinder | Destroyer | PD2
Aces: 8 | PDGA# 56345 | GRIP# 2033