Cellular update failed

My iPhone 7 has been on IOS 15 for a few days, and today it randomly stopped connecting to data and now is saying Cellular Update Failed, Your iPhone cannot make and receive calls or access cellular data until it has been updated. Ive tried resetting my settings, connecting to iTunes on a computer and checking for updates, nothing will work. I also have no access to my cellular settings, it just says error for the tab and when i click it says the same popup just on the page itself rather than a whole popup. please help?