I had a class in music history many moons ago. During this class, the prof discussed how Beethoven had several endings to his 5th symphony. There were different cording progressions and feelings emoted with each ending until the one we now hear was penned. Also noted was the existence of German curse words in the margins of the portions that were not used.
I have another song on which I worked a couple of weeks ago and have left in the crock pot of my mind to simmer for a while longer. The melody was picked and I tried working on harmony including interesting cord progressions. As I would get the harmonics to work and find an interesting sound, I would go back to the manuscript and discover that the end of the progression had nothing to do with the melody at that point. I won’t say any German curse words, but can understand the frustration.