Apple ID - old email address
My iPhone has always asked me to enter my password for my Apple ID in settings, however this has always been for my old email address which I have since changed. For the past couple of days this message keeps coming up every 30 seconds and 3 times in a row and is very frustrating when I'm trying to do something on my phone. I've tried logging out of my account, turning my phone on and off and trying to enter my password even though it won't accept it. How am I able to fix this problem? Because it is very frustrating.
iPhone 6s, iOS 10.3.3