If your revisions are making you writhe in agony, that's your gut telling you something important. Keeping your vision while making revisions is essential.
So many times a writer is anxious to make whatever changes a publisher or agent suggest they don't consider if it will benefit the story being told. The author has some difficult choices to make. And a few questions to ponder before ever changing a word.
~ how will this change make the book better? Will the heart of the book remain?
~ is the writer still in control of these changes? Or does it feel mandatory in order to make a sale?
~ has the publisher/editor/agent simply pointed out a problem or a hot spot that needs fixing? Or would this change be a significant transformation to the script?
~ Is the publisher/editor/agent trying to make this book fit a popular trend or would the reworking open the eyes of the reader in a way the author hadn't considered?
I'm sure you could add several more scenarios to those questions mentioned. And I'm not saying to ignore good advice. I'm suggesting the writer take into account what's at risk and think through the purposed revision before tearing into it. If the feedback feels genuine, ... "the dialogue is stilted, your character lost her pazazz, you need more here, this is too long ..." are all great pieces of advice to make a book better. Most writers would readily set those mistakes right.
If the revisons requested feel off target, talk about it. Defend your work, politely of course, but defend it, discuss solutions that will work for everyone. If you don't speak up, you'll have no one to blame but yourself for not acting on your instincts to protect your storyline.
Working with others regarding your manuscript is called teamwork. Group effort will make your book the best it can be. Just remember to keep a hold of your voice, the heart of your story and your style. That's your vision, your work!
Til next time ~