Problems deleting Meta a/c

Hiya

Sorry in advance :-(

I'll try to keep it brief as poss.

Had Facebook acc for YEARS (linked to old email address that I no longer have access to) - Don't really use Facebook.

Bought Quest 2 few years back, set a/c up, that's not linked to my Facebook.  At some point, I've done something on headset (i think) and possibly created a meta acc that is linked to the Facebook profile.

Sold headset last year.

I set up new Facebook acc about 6 months ago, so now trying to delete the old Facebook acc, but can't because of the Meta link.

So in the Facebook page, gone to 'Settings & privacy' then 'Meta Accounts Center', then tried a few things, and I keep ending up at:

"You need to create a password for Ms Blahhhh

This account uses login info from your Facebook account (Ms Blahhhh) to log in.

You'll need a new password so you don't get locked out"

then a CREATE PASSWORD button.... which when i click on it, I'm taken to:

"Enter the confirmation code"

Problem is, its emailing the code to the email address I don't have access to.

I've tried adding a new email address and tel no to the Facebook acc, but can't see how I can get the Meta 'Create a password' code to go to that email add.

I have got to a screen that mentions "don't have access to this email address" or something along those lines, so I clicked that, but it then wants a serial number for a Meta device.  Which I don't have!  

I am planning to get a new headset but its probably going to be next year.

Also.  I do have another meta acc, that has all my purchased games on - i set this up when i bought the headset.  There is no history, friends, purchases etc on this acc I am trying to delete.

Can anyone advise how I can get round this, or how I can log it with Meta??

Many thanks