How to sync ALL 100,000+ photos between two Apple IDs that share iCloud storage and have family sharing?

My husband and I have been married for 19 years. We have at least 100,000 photos stored of our life together. We shared an Apple ID for all those years. A few months ago we decided that one of us should get a separate Apple ID because it was causing little issues sharing one ID between two people. I made myself a new Apple ID, added myself back into our family sharing account, synced our icloud storage together and synced our photos. The problem is that it is only showing me a random spattering of about 5,000 photos from our 100,000+ number of photos!

It is driving me absolutely nuts that I don't have access anymore to our family's complete collection of photos throughout the years anymore on my iphone. The only way to access them all is to log in to my husband's apple ID and manually search them that way.

Every web search says we're supposed to make a shared album and manually put the photos in that we want to share. That is a preposterous undertaking, to add 100,000+ photos to a shared album?! Plus, a google search will tell you there is a maximum of 5,000 photos in a shared album. Help! Why can't it sync ALL photos between two Apple IDs that share the same iCloud storage and have family sharing? If there is a way, please help me understand how! Thank you!