I've had my facebook account for around ** years now and started it with an email accou...

I've had my facebook account for around ** years now and started it with an email account that I haven't used for years and don't have the details for now so can't access. Some years ago I created a new FB account with my current email address, but never actually used it - continuing to use my original account instead. I would like to change my current FB email address to the one I'm using now, but FB won't let me as I've already used this email account (for the account I made but never use). I have since deleted this account but am still having no luck as FB still says the email address is in use. I would like to be able to receive my notification emails and access my FB account through email so really want to fix this but not sure how.