Sent token to a wrong address

I sent 30 ETH to the wrong address. So I copied the ETH address from my account where it says copy to clipboard, now I don't memorize my ETH address so I just copied what's there. Two weeks have passed, I did a self retrieval and it's still not on my account. I contacted support and they said that what I gave them wasn't my address. Prior to this my account was saved on my laptop with a different password despite never opening my account on that said device. I don't know what to do it's a large sum of money and I need any advise you can give me. Thank you.