Apple ID missing

Background summary.

I have an iPhone5C which I use while travelling which I gave to my wife when she was visiting our grandchildren overseas and she got a US SIM.

Somehow she changed my AppleID (which is used for family sharing) to hers in an attempt to login to iCloud.

This morning I discovered my iMac (in Sydney) thinks I am her.

I attempted to sign out of her AppleID (she didn't know the password so I reset it)

Now when I try to signin with my AppleID I am informed this no longer exists!

 [email protected] is not an Apple ID.
If you have forgotten your Apple ID, you can look it up.

I logged my iMac into my wife's AppleID (if that actually was her AppleID).

Just to be clear this is not any kind of family drama and simply - other than technical confusion or perhaps a dialog / unintended change to set up a different account.

It now appears that this was NOT my wife's AppleID, but some other email address she has.

Is it possible that my wife changed my AppleID?

It now appears that my wife actually changed my AppleID (although exactly HOW is unclear)

I went to appleid.apple.com/ and have now restored my name, birthday and AppleID

When things settle down I will reset the password to something more sensible.