I'm no expert, but from the (excellent) feedback I received posting my own video, it sure looks like you're making yourself release the arrow and not pulling through the shot. Need to increase back tension and never stop pulling. The draw elbow should come back and slightly around. At the moment the arrow leaves the string should still be increasing back tension and aiming (whatever method you use), and the release will just happen. It helped me alot to just remove release from my mind completly, don't even think about it, just concentrate solely on aiming and back tension and when all is right the shot just happens.
Good luck!
I'm sure those far more knowledgable will weigh in soon and probably be able to explain better than I can.
Travis