When you are whip stitching the two pieces together you will just be catching a thread or two from each piece. You will not be catching the paper into your whip stitches. It is not a fast process, but in that "selfsewn" tutorial you can see how she has her two pieces laying face to face on top of each other.... and then using just the point of your needle catch the threads from the very edges then bring your needle back to where you first entered but move over only a couple threads. Don't give up.... keep trying and you will find this a very fun project once it " clicks" . I wonder if there would be a shop near you where you could pop into for a "face on" demonstration, sometimes we need that to help.