March 2019
As it turns out, you cannot "switch" EA accounts on PS4.
Games requiring an EA account on PS4 will automatically search for one using your PSN email address, and if none is found, they will automatically create one and link it on your PSN account.
Try logging in on ea.com with your PSN email (worked for me while searching which account Anthem and Dragon age were using).
Like you, I have played many EA games in the past, some of them on PC (like Crysis 3) which required an EA account. But saddly this "PC" account cannot be linked to my PSN profile because it uses a different email.
November 2019
December 2019
The email address that is associated with your EA account can actually be seen in game under Settings>Account.
How to find your EA account email address in game: https://help.ea.com/en-us/help/account/find-your-ea-account-email-address-using-your-game/
If you login to our Help site at Help.EA.com with your PlayStation or Microsoft credentials, then select Account at the top>Change Email Address, you'll see what email address is linked up to your Gamertag/PSN ID as well.
This post is from 2017 and I'll be locking it down. If you still need help accessing your account information or need assistance updating it, please contact our Live-Support team here.