You really set yourself up for a lot of anxiety by choosing double-yolkers for your FIRST hatch and then having to leave at the most critical times! Not to mention these are ducks and ducks always take their time compared to chickens.
Learning how to properly assist takes some experience and intuition because a lot of it is all based on your best judgement in the moment which can be poor if you dont have past experience with it.
With help you can certainly have success, but perhaps in the future before doing this again you should practice on call ducks, they’re awfully hard to hatch and so unbelievably worth it