Is it worth restarting Binding Blade for the secret level?

Hey all! I’ve been playing through binding blade and really liking it. I made it all the way to chapter 14X. I looked up what divine weapon I got here, only to realize that I’ve missed some of them in chapter 10 and 12. My team is also really struggling and the game has gotten quite hard. I’ve lost a handful of units, but haven’t bothered restarting the chapters.

Should I start a new play through to make sure I get all the divine weapons and can get the true ending? How much harder does the game get from here? If I’m struggling now, it might be worth it to go back and play more optimally to strengthen my army.