IPHONE NOT UPDATING(STUCK ON VERIFYING PROCESS) AND MOBILE DATA ERROR

So out of the blue, my iPhone had a mobile data error and kept on saying "an update is required to use mobile data on this iphone". I tried everything I saw online. I rebooted, force restarted, reset network setting and all that. Finally I updated the phone. When I clicked install after downloading it kept on saying “verifying update” for more than hour. I couldn’t do anything while it was verifying, I couldn’t leave, switch to another app. I had to hard reset the phone and started all over but it got stuck on the verifying process again. Please I need assistance, im honestly tired