Yeah, I've always had a bit of a ducking problem. Do you know how I can get rid of it? It drives me nuts! And usually my leg is pretty stationary, I have no clue what happened in this picture! Lol
WELCOME!! I hope you find a lot of friends here.
Well, you pivoted on your knee. Possibly gripping too much with it. Knees hard on the saddle tend to break the lower leg away from the horse's sides, allowing it to swing back. As your upper body goes forward and your lower leg slides back, you become VERY front heavy. As a result, you are resting on your hands...using them to prop your upper body up.
I would practice two point with no hands at all gaits. As your upper body goes forward, counterbalance it by keeping your lower leg forward. This will counterbalance the upper body. You will, probably, have to stretch the muscles on the back of your legs.
Go in two point and REALLY move those lower legs forward until you can hold the two point without hands. You will feel the muscles along the back of your leg burn!
Until your leg stays forward (at the girth) when you jump, your position will be very unstable. Sometimes I have seen trainers hobble the stirrup to the girth so that it stays put.