Here’s my to do list from myself of things to fix in the book, just in case you’re interested:
Give the heroine A. a goal B. a spine C. her frontal lobe back.

Fix the first half of the book, in which our heroine is Too Perfect. See above.

Go for the low humor, you know you want to. I don’t know how you resisted the first time around.

Get hero and heroine interacting from the beginning. It’s a romance. The hero and heroine need to interact.

And my theory is that by making these changes I will fix the issues in the first and second acts which will then resolve my problems with the third act. It all builds, and if your structure doesn’t have a solid foundation, that’s a big problem. My foundation is weak, which is why I’m tearing it apart and rebuilding. I have the “how”, the specifics on all these points, but I’m not listing ’em because that’s spoiler territory. But that’s my to do list.