1000s of photos deleted!

For the past several years, I have used the google photos app as my main photo app on my iPhone. I have had sync on, so photos taken on the iPhone go to google photos as well as the native iPhone camera roll. I have used the "Clear up Space" feature to delete photos from the iPhone camera roll and keep them in google photos. This has resulted in a google photos library of over 2000 pictures, and an iPhone camera roll of a few hundred precious photos. I am certain these images have been backing up, as each time I open Google photos, the new photos are shown backing up with the cloud icon. Today, I opened up Google Photos, and was met with a popup (see pic) prompting me to "Back up" or not. Confused, I clicked back up and proceeded to the photo library. However, only those few hundred photos which were saved to the iPhone camera roll were there, and the rest had vanished without any trace. all of my facial recognition information was gone, as i was prompted to "pick which face was mine" when before I had already made a folder with photos of my saved as my name. I never clicked a delete button, my archive and trashcan  are both empty. Thousands of photos have disappeared and I feel so helpless! Please help me get my photos back!!

https://preview.redd.it/pzh9qg3anak81.jpg?width=1242&format=pjpg&auto=webp&s=b4c50d40d87e019ef17d6688d5af6e4a12c87eff