Unable to verify update

I have been attempting to update my iOS for several days now. I can download the update, but when I hit install, the "verifying update" pop up and circle comes up. The circle spins around and around for 3-4 minutes, and then a pop up comes up and says "iOS 15.0.2 failed because you are no longer connected to the internet." I have spent about 20 minutes total staring at my Wifi bar and it's always full, despite my phone saying I am not connected. I've even tried installing it via cellular data, but the same thing happens.

I've also tried the following:

Hard resetting my phone.

Tried using three different Wifi networks.

Deleting the update and downloading it again.

Deleting 10gb of data off of my phone, making my available space 70gb.

Nothing has worked and I'm really getting frustrated because now I see that update 14.8 never installed either, but the same thing happens when I try to install that update.