Changing active user in Microsoft 365 when you are blocked from the email account

Hi all,
Really hoping someone can assist me.
I have recently been blocked out of my email due to “insufficient information” to verify my account. I gave up with that email because there was absolutely no way I could put any more information into the form to verify it. I created a new email and all is well, until now. I’ve just realised that the OneDrive account and complete Microsoft 365 personal account is linked to this inaccessible email address. I need to change over the access to this new email address however in order to do that it seems I have to sign into the old account.... which I don’t have access to. Can anyone help me with this problem? Please please please.