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?