OK, if you have provided VM with a GMail email address in the past, when you previously had the password reset, that is what you use as the username when you log into 'My Virgin Media' or VM webmail for that BY account.
You need a 'VM password' to go alongside that Gmail address to be able to log into 'My Virgin Media' or VM webmail for that BY account.
The only use for the 4-word password is if you were setting up an email program such as Outlook, Thunderbird etc.
If you don't know what your 'VM password' is to go with that BY account try the reset link below
https://www.virginmedia.com/identity/forgotten-details/password
Enter the Gmail email address on the reset page above and I believe it should send a verification code to your Gmail address to allow you to reset the password.
Unfortunately I ditched VM email a long time ago so can't test any of the above info (which I have cobbled together from other posts on the forum).
Try that and see if you can reset the password on the BY account.
If the password reset works, and you can create a new password, then in future you use the Gmail email address as the login name and the new password you create to access 'My Virgin Media' and webmail for that BY account.
The BY account should function just as it did before. The Gmail address is being used as nothing more than username to access the BY account (and to receive security resets)
