Apple-ID Login Fail - country issue?

Hi Community,

I lost my old iPhone and bought a new one and wanted to set it up with iTunes.

Everything worked fine but I cannot Log in with the Apple ID.

The problem is probably that I did the last Synchronisation with iTunes in Germany half a year ago and now I live in Australia.

I already changed the settings and Appstore to Australia but never backed it up with iTunes.

Now I can't change it back and I get a Login failure everytime and I think it is because of the country issue. Online it is no problem to log in for me.

I hope that there is a solution to my problem :/