iPhone storage so full my photos disappeared bug

My iPhone 12 Pro has been full for a while, I had about 100gb of photo and video. I lost 95% of the photos last night but i think the data is still on my phone but it’s stuck in “system data”

It all happened when I finally got around to backing it up. I used Microsoft store iTunes (unfortunately) first. I went to get a drive and unplugged the phone (it wasn’t running anything yet). Then it got stuck in a weird boot loop, and would load to the homepage but was glitchy and not showing all the icons. At first I could see all my photos still. I went to delete some old longer videos it would say they deleted but they were still there, then suddenly a huge chunk of them disappeared.

I downloaded iTunes from Apple and it made a backup of the phone successfully (but with the block of unreadable system data). I updated to newest ios and the phone works again, still full but can’t see photos.

This wasn’t completely backed up to icloud. Feeling pretty saddened that I just lost all these memories but I have hope because the system data storage exactly matches the volume of photos I used to have.