Steam Account Linked to New EA Email by Mistake (Need to Re-Link to Original)

Hey there, once you unlink a platform account from your EA Account and link it to a new one, you can’t unlink it again for six months.

For your Apex account, the progress is saved on your EA account. So if you still have access to the EA account where your Steam was linked to, you can try to download the game on your EA app and log in with the EA account that was linked to your Steam account previously. Then download Apex Legends through the EA app and check if your progress is still there. It's not guaranteed that you will be able to recover the progress as the accounts have been linked, but it's worth checking it.