Stuck in email change loop!

One of the email accounts on my account has ceased to function, it seems from reading the advice because I need to generate a mail app password.

On logging into settings I was asked to change my email to a secondary email account, which I did and then used the verify link sent to that email. That email account is now showing.

However when I log into settings and click the "manage" ink to generate a new mail app I am asked to verify it is me and change my email - I click on the link and am taken back to the settings page, which shows my already changed email. If I click on the "edit" email account link, i get routed to the same box asking me to verify my id and change my email, cicking on which also redirects me to the main settings page.

I am now left unable to access the email account but also unable to do anything else with the account.

Please help and advise!