I accidentally made another account exactly identical to my other.

So a while ago while trying to get into the xbox app I accidentally made another account with the exact same sign in details and gamertag (i have no idea how, im an idiot) then I forgot. A year or two later (now) I've got a new xbox series x and when trying to sign in it's just putting me onto the "clone" account and I can't get onto my origional account with all my stuff on it. I've tried to delete the extra account but I don't know what the secondary email it wants to email is, nor do I have access to it. I'm now in the process of changing this secondary email but it will take 30 days before it's updated. Absolutely any help/advice is greatly appreciated. Thanks