Forgot Origins Username and email

A couple weeks back I got The Sims 4, and loved it! Great game, but I tried logging in and it didn't work, I've tried every Username and Password I could ever think of. So far I've gotten into two of my Origins accounts. I'm pretty sure I had made three. I got into my original Origin account and it only had my sims 3 games under My Games, which made sense to me. I Had recently made another account for The Sims 4 Demo, so I tried that one. The only game under My Games was The Sims 4 demo! I tried reset password and typed in all my e-mails I've had and never got an e-mail from Origins. I checked all my files and everything, but still nothing. I tried just reinstalling it onto my Origin account, but when I typed in my registration code it said it had already been used. I really need some help!