iPhone storage space not going down even when deleting lots of photos and videos?

So, I have a huge dilemma. No matter how many GB of photos and videos I delete, it won’t change my storage space. It’s at like 252GB used out of 256GB.

I need to update my phone to fix the bug or whatever but I need more storage space to do that and I can’t do it.

On top of that, my iCloud backup is failing so it won’t back up my June and July photos but it’s done august ones and the rest of them.

I have an appointment tomorrow at Apple Store but does anyone else here know what to do?

It’s almost my birthday and I’ll want to take photos.

I also can’t really upload them to Dropbox either because it takes so much time and I may need more storage space to do that too.

Any tips??

Edit: I did delete everything in recently deleted, so don’t comment that I should do that like I’m dumb or something