Hey xoRyuzu,
To clarify what caused this, progress is stored on the EA account level, not on individual platforms like PlayStation, Xbox, Steam, etc. This means if you link your platform to a different EA account, you'll lose access to that progress and it will appear to have reset. Progress cannot be moved between different accounts.
What happened here was that you moved your PSN account from one EA account to this one. The progress you'd made while playing on PlayStation previously would have been left behind on your previous EA account when you had moved the PSN here. This means if you're trying to restore any progress, you'd need to re-link your PSN account to the prior EA account.
Note that will also mean you'd lose access to whatever's on the current EA account. Unfortunately there's not a way to combine progress that's on two different EA accounts, so you'd have to make a choice which to keep, or just keep the platforms separate.
We are not able to make any changes to your account status or progress via the forums, but if something was linked or unlinked incorrectly it may be worth contacting support to see if the original platform can be re-linked.