Hey iithejagii,
Is the PlayStation account one that you have access to or are familiar with? If so, you'll want to sign in and play with that account because an EA account can only link to one account per platform in its lifetime. Unfortunately, you won't be able to link a new PlayStation account to the same EA account, even after unlinking the current one. So it'd be best to try to regain access to the PlayStation account if you previously owned it.
Generally speaking, if you'd like to play using a different PlayStation account, you'll need a new EA account as well. However, if you haven't already, you could try reaching out to live support to see if they can help override the original account link. Please note that unlinking accounts always comes with some risks, so proceed only after you've taken a moment to understand them.
Let us know how it goes, thanks!