But I was only ever logged in in Germany. It would be really nice if you could help me. I still have my email address + password.
But unfortunately I can't get any further because of this message. Would appreciate an answer very much. Many Thanks.
If you didn't take the precaution of setting a recovery telephone number or keeping a secure backup of your 2fa secret key you need to do the following to prove ownership of the account (2fa is used to protect accounts in the event of their email getting hacked).
Sign a message from the Bitcoin address in the profile or an address you previously deposited from. The message needs to contain the user ID of the account, the instruction to reset 2fa and today's date.
Then send me that message in a PM.
Instructions on how to sign Bitcoin messages can be found in this thread: https://bitcointalksearch.org/topic/how-to-sign-a-message-990345