Sorry to tell you but there's nothing we can do about it. Once it has been transferred there's no way for you to reverse it back. It's your fault, maybe you signed up from airdrop or something. Heads up, if you're going to use MEW make sure that you don't put all your ETH and altcoins in the same wallet.
all my security measures are on
It is likely you left something out or your laptop had some sort of malware unknown to you. It is impossible to move your tokens from you wallets without some sort of security breach.Unfortunately, such transactions are irreversible as far as I know.You might want to reconsider the use of a hardware wallet henceforth,especially as you hold quite substantial amount of crypto. So sorry for your loss.