Hey @v7igtnz1scny,
It looks like the EA account you're posting from was just recently created, so if you've played at all in the past that seems to have been on a different account.
Your progress is saved on the EA account, so re-linking a Steam account from another EA account to this one would not transfer that progress.
The only way to restore that previous progress would be to re-link your Steam account to the original EA account. This would be why support was providing that message regarding the effects of unlinking an account.
We are unable to assist with any account changes on the forums, so if you're unable to proceed with the steps in the link above you'd need to contact support again so they can try to help get that re-linked to the correct account.