Changed my iCloud email; Now I can't log in.

Dear Community,

I'm having the same issue as this user did three years ago and it seems their question was never resolved either. On my ipad in order to get icloud to log in using my new email address I am being prompted to provide my password. I've tried old ones and new and it doesn't work, responding with incorrect password or a verification error - duh, I changed the email address. I want to move the photos and comics from this ipad to the cloud as well as the apps so that I can upload them to a new one. This is incredibly frustrating and not at all intuitive or user friendly. Any advice?