Photos Library Contents Gone After Attempting Backup on Amazon Photos

I was attempting to back up all of my pictures onto amazon photos since I have unlimited storage there through prime. After the initial backup It still had not uploaded the contents of my photos library so I tried again. Not knowing where the photos actually live I googled how to go about backing up photo library pictures to amazon. What I found said to go to file explorer and drag the photos library tab into the backup window in order for it to back up the file. Now all of my photos (16,299 of them) are gone. The photos library has been replaced with a handful of pictures from my downloads.

I tried time machine already, but apparently It hasn't backed up anything since 2016, so no dice there.

Does anybody have any advice for me?

I didn't delete anything, and I don't really understand what happened. My thought/hope is that everything just got moved somewhere or I broke some kind of link that needs to be repaired.