only 3000 photos yet it’s taking up 21gb storage on my phone?

i had around 13,000 photos/videos (dating back quite a few years) that were downloaded onto my icloud. i got fed up of needing to keep buying more storage and decided to just turn it off & then keep only the most important photos on my phone.

but after getting a notification saying my storage was low, i found out that the photos app is currently taking up 21gb of storage. this would make sense if these 13,000 photos were now just in my camera roll not downloaded however they’re nowhere to be seen. i don’t know where these other photos are so i can’t delete them. they’re obviously no longer downloaded on my icloud right? (so i can’t just log in to it & delete them that way?) but they’re also not actually on my phone. i did turn icloud photos back on to see if they would all download back onto my phone but it’s been stuck on 1% downloading for hours now. i’m so confused!

i have all of these photos backed up safely elsewhere, so losing or deleting them forever is fine and not a concern at all. i just don’t know HOW to do that as i seemingly don’t have access to these mysterious missing photos!

so in a nutshell, i currently only have 3,174 photos on my phone (none in my recently deleted folder either) but the photos app is taking up 21gb of storage and is saying that i should upload 17gb of that to icloud.

when i try and turn icloud on for photos, it doesn’t download past 1%. i literally have no storage left and seemingly no way of freeing some of that up either. what is going on?.