iTunes computer remote deauthorisation

All of a sudden my iTunes on Windows 10 wanted me to authorise. It was previously authorised. When I entered my details it said I can't authorise as I have already authorised 5 computers (didn't know about this before). The problem is I don't have any of the computers which must have used the previous authorisations. As I can't authorise my current computer I can't get at the account settings to deauthorise all computers as described in the Apple support guide https://support.apple.com/en-gb/HT201251. I all so tried changing my password with the 'logout all' checked, but that didn't help.

Is there a way to deauthorise all computers remotely or do I have to dump my Apple ID account and all the pain that would bring?