How do I remove an unwanted alias email and restore the primary email on my iPhone?

I am not able to delete an alias email, such a weird problem. My child accidentally added an alias and now my phone associates with the new email vs the actual account email. No big problem right, just change it back to the main email? No... The primary email is already the primary email when I log in to my account, but the alias is there, but cannot be deleted. Please see attached picture, the alias is the bottom email. There is no way to remove this alias, it is not the primary email, but it acts like it on the phone. I am sending iMessages from the email also instead of my phone number, because the phone number is also not associating with the account on the phone now. I am not able to remove the email from my primary phone on the account. It is stuck. Please help.

[Re-Titled by Moderator]

Original Title: I am not able to delete an alias email from my phone, and its taken over my iMessages also