I find it a little hard to see but on the surface, it looks as though you are coming a little past your anchor then sinking back to it. This is why you are creeping I think. Once your motion to the back reverses, it is hard (if not impossible) to get it back even though it may feel like you do. Try drawing so you come directly to your anchor, set your references but keep increasing pressure towards the rear. This is easier to learn with a very light bow or a rubber band and in front of a mirror to get the feel.