How do you find your EA origin account for Battlefield Hardline?

I have been playing Battlefield since Bad Co. I have since then changed my gamer tag and can't remember my original sign in with my EA account. when I installed Battlefield Hardline on my Xbox One, it asked a question and I clicked the "ok" option. And now it shows my origin ID as my new gamertag, SouthrnRenegade. Now I can't seem to access my account to check out the cool rewards I've unlocked in battlepacks. Please help.