changing my apple ID

I just changed my apple ID to my email address, rather than my husband's. The process seemed straightforward, and when I go to Settings--Name, Phone Numbers, etc, it indicates my apple ID is updated. However, on the main Settings screen it shows my name with my old Apple ID beneath it. Furthermore, there is a red circle indicating I need to "update Apple ID settings." When I follow this link, it wants the password for my OLD apple ID. When I enter that, it says "verification failed" and yet there is no option to fill in my new Apple ID...and I am using the correct password for the old Apple ID. Any help would be appreciated!!