Hey Kirito13a,
If you were directed to the forums, what we're able to assist with in these situations would be feedback or clarification. I'm afraid we cannot assist with any account changes or discuss account details here, as these are publicly visible boards.
From what you've mentioned, it sounds like this is due to unlinking a platform (Steam) and linking it to a different EA account.
Progress is stored on the EA account level, not on individual platforms like PlayStation, Xbox, Steam, etc. If you link your platform to a different EA account, you'll lose access to that progress and it will appear to have reset, which is what's happened here. Progress cannot be moved between different accounts.
If this is the same Steam account you had used in the past, it is now linked to a different EA account. That's why you're not seeing any progress - it's still back on whichever EA account was used originally.
This can cause the progress to be permanently lost in some cases, but you may be able to recover that progress by re-linking your Steam to whichever EA account you had used in the past rather than this new one. If you're not certain which EA account that was, this is where our support team may be able to help verify and update the login details and connected platforms for that older account.