Creating a world : United under whalefall

I have been working on this world idea for a long time. Maybe a year. I just want to share as much as I can on here about it because i feel I have no one to talk about it with in my day to day life I was hoping some people on here might think its interesting.
It started a few years ago I was listening to a nature documentary and it mentioned a phenomenon referred to as Whalefall. For those unaware a summary of this event is when a whale dies and sinks to the bottom of the ocean it becomes a ecosystem that many things feed on an thrive around. It could take up to 2 years for just the flesh to be stripped and the bones or "skeletal stage" can last for decades. Thinking on this island wondered what would life be like if this was our world? A dark world barely seeing light , Barren cold deserts with pockets of thriving scavengers picking meals off of dead creatures. I started calling these creatures Leviaforms and as I thought about where they would come from I had the thought that maybe they were biological machines. Created to terraform planets by a species of ancient aliens I noted as "the others" in some of my first drafts. This led to the idea of what I called "bloom events." So instead of rotting away these Leviaform would explode outward or "bloom" alien and earthly fauna/flora as it rewrote things to be like its home world. Iv tossed around a bunch of ideas for this world and have alot written out about it and how people have survived around these pockets of bloom. Every time i feel like iv commited to some particular idea though I feel as though im making the wrong decisions. This world i created was not ment to be this complicated I just thought it sounded cool but has now spiraled into an obsession of finding out the best way to tell this story without over complicating it for the readers or even myself. Im new to writing and world building but this idea has effected me so greatly I feel I need to share it in some way just enough to get it off my chest I know thats alot and If you read all this thank you for your time . I'd like to end by asking Why is world building so hard but addicting And does any one have tips for organizing my worlds lore