I think you're doing a great job. It's about practise!
What I can say is that you should try to plant your forward stroke in at the toes. Always. When you do your double pump you're putting the blade in at the hips, which means your stroke is shorter and less powerful. Take a longer, more powerful stroke. You'll get it, it does take some effort to nail it down consistently. And good job on getting video footage, very helpful. Good luck!