Years of photos and videos missing from iCloud

I noticed today that I had significantly fewer videos and photos on my iPhone 11 Pro than I usually do; notably, my favorites album went from probably 20 photos/videos to just one, and the total photos dropped from nearly 2,000 to just more than 200. The missing photos and videos date back several years; it looks like everything I personally took prior to early June 2023 is gone. I have not changed any settings or installed an update recently. I have 200GB of iCloud storage and had no problems with storage on my phone. The missing files are not in the recently deleted folder nor the hidden folder. I am absolutely devastated; I bought the iCloud storage specifically to retain my photos and videos. I do periodically backup to a hard drive, but have not done so in a very long time...probably since I decided to buy iCloud storage. Please help me get those memories back!