Pretty sure this is a common problem with most if not all writers. We write something and then insist that every single word after that correlates with those first words. That’s not how it has to be. This isn’t a perfect world, you’re not a perfect person, your writing isn’t perfect. You can use that delete key!
Just because the new something you wrote doesn’t follow previous set rules doesn’t mean it’s wrong. It could be the previous work that needs readjusting. As soon as you realize what you’ve done, sit and think. Which is best? Which will provide the best experience for the reader? Can’t decide? No problem, leave a little side note and come back to it when you’ve written more. A lot of these things take care of themselves. Right now the planned ending for my current piece is a cliffhanger. Readers don’t like that, but I’m not sweating it. I know things will change a dozen or more times before I get there, and I can worry about it then. (Of course I’m still holding out for not having to 😉 )
Can’t bear the thought of removing or changing your beautifully crafted words? No problem. Cut them out and paste them in a special section title “removed” or something like that. (If using Scrivener, be sure to paste them in the notes section instead of the actual document area to prevent an off word count.) Those words are not lost forever, and yes, I have actually gone back and used them on multiple occasions. One thing I do is before transporting my piece from Scrivener to Word, I reread all my notes, deleting the ones I’ve taken care of or are obsolete and then doing the same with the removed section. By the time I’m using Word, my piece is to the point I know what I will and will not put back in or throw away.
Good luck with your writing, and don’t be afraid to contradict your previous work! It may just be the best thing for it.