I'm glad you found this piece helpful! I frequently find myself in a similar spot with an initially small, manageable idea ballooning into something more elaborate and unwieldy than I expected. Perhaps my favorite site for advice and resources on plotting and story structure is Story Grid (also linked above):

https://storygrid.com/resources/

I'd highly recommend the articles under the headings "Story Grid Tools," which helped change how I think about storytelling and are particularly helpful when you've already finished a rough first draft (or part of one) and are massaging it into something streamlined and compelling.