You can only have one PSN ID linked to an EA Account at a time. If you previously unlinked a PSN ID and then linked a different one, that’s likely why your progress appears to have been reset.
If you’ve never linked a different PSN ID, then your progress normally shouldn’t be affected. Unfortunately, we can’t check your account connections here on the EA Forums, but you can contact EA Help. They should be able to review your account, confirm whether a PSN ID was previously unlinked, and provide more information about what happened.