How can I remove my EA Account from The Sims installed by Steam?

Hello,

I installed The Sims 4 using Steam. After starting the application EA App was downloaded and I created the account. Unfortunately, I misspelled my email, but the account was created and the game started. 

Now it is not possible to change my account in EA-App. When starting the game from Steam it log-in automatically. I cannot logout in EA App, when the game is running.

Is there any link between my Steam account and EA App account? How can I delete i or change the email/username? I tried to reinstall the game using steam, but with no help..

Thanks

Elisa, The Queen VI