How do I move my structured hierarchy of Windows folders to my iCloud Photo cloud?

Over the years I have painstakingly managed my photos, placing each one into an album which is a Windows folder. I've pulled off of my iPhone and iPad camera rolls to do this in order to maintain free space back when it was at a premium and have commingled them with photos from other cameras as well.

Now I would like access to all of those photos via iCloud Photos, but I cannot drag and drop the folders into the "iCloud Photos" area on my PC. Do I need to create a "new shared album" in the iCloud Photos system folder for each of the dozens of folders and then move the photos group by group?? That seems insane and will probably put me off from using iCloud Photos at all.