Go to your Google account, go to privacy.
Change/Hide your name/email by logging in.
I don't know about the "anonymous" thing, but if you were to hide your email/change your name you wouldn't feel the pressure.
Might not be someone hacking your phone. However they were mine. They gain access through your Gmail accounts and go through the back door of the web. I do not know all the computer lingo or terminology, but my case was proven. Once inside they can download and hide apps from Google play store or or even samsung galaxy. They are even appearing as my IP ...
As the image reads "That username is taken". So, you have to try using a different username.
It happens when someone has already registered an account with that username. But in your case, it is not allowed as Google has some policy on certain usernames. Best would be to try another combination.
Also see: https://support.google.com/accounts/thread/...