Hey ReeBeQYT,
Generally speaking, if you're looking to change the email address on the EA Account from an inaccessible email to a different one, you can do so by contacting live support, who would complete that change on the account side. Any in-game prompts would likely not correspond to a change in the EA account, but would be game-specific.
This page includes the steps you would take if the email address were accessible, but in this case, it's best to use the Contact us option at the bottom to reach live support, as you've already done. Once you connect with an advisor and answer their verification questions, they should be able to work with you to get things updated from there.
Let us know how it goes, thanks!