I understand your question now. Thank you for explaining.
The best way to check if your Steam account is linked to your EA account is to login to your EA account with a web browser and click on Connections.
https://myaccount.ea.com/cp-ui/connectaccounts/index
If you see your Steam account on there then it's already linked to your EA account. You can't unlink a Steam account until 6 months have passed since the account was linked. EA requires accounts to be linked for 6 months before they can be unlinked.
https://help.ea.com/en/help/account/unlink-gaming-accounts-from-ea-account/
Keep in mind once a Steam account is linked to an EA account it's a lifetime link and that EA account will never accept a different Steam account link. EA most likely does this to prevent game sharing.
You can create a new EA account if you want to link a different Steam account to it. You can even unlink a Steam account from an old EA account and link it to a new EA account I believe. As long as 6 months has passed.
I'm not sure if support will be able to help you or not. All you can do is contact them and ask. I hear contacting EA support can be difficult.