Warning message that my account doesn't support use on more than one machine.

I hope for your sake that you have up-to-date anti-virus and anti-spyware on your system and that you use them regularly to safeguard your computer.

and if you need to change countries, the country associated with your adobe id must match the store you purchase from and must match the payment address. otherwise, change what's necessary:

change your country on adobe.com, https://www.adobe.com/international/selector/

change country associated with adobe id - https://helpx.adobe.com/x-productkb/policy-pricing/change-country-associated-with-adobe-id.html

change credit card and/or billing address, https://helpx.adobe.com/manage-account/using/update-billing-information.html

change currency - https://forums.adobe.com/thread/1999694

change store - http://www.adobe.com/store_selector/storeselector.html

change adobe.com website language - https://forums.adobe.com/thread/1999693

change age - https://helpx.adobe.com/nz/creative-cloud/kb/you-eligible-cc.html

if you're still seeing that message:

go to your account (https://account.adobe.com > plans & payment > activated devices) and sign out from all computers.

then enable 2fa, 

sign into your computer(s).

To confirm, what type of license do you have? Are you using a Creative Cloud single user subscription? If so, have you tried changing the password to confirm this is not the case? Or are you using VPNs or a unique environment that could make the software think that you are logged in simultaneously that we may be able to help provide guidance with?