Damn, this is no small money, op I can't imagine what you must be going through at the moment because this really sucks, especially seeing that no help is coming from any place, my question is, shouldn't binance have a plan for case like this, after all it was their api that was used, there should be a way to resolve or at most block a wallet with such incidence so that the hacker don't go free with such money, very disappointing that both binance and tether don't seem to be able to help.
after a lot's of search I found this : Etherscan Phishing Form
https://docs.google.com/forms/d/e/1FAIpQLSf8vsYLkm8QA8il615yS0gqCNmWWfLArFM1o4-R5xmV-0fbYg/viewformjust to report that you lost your money and you must prove it , seems its just for phising
You should contact the binance support and request them about from where the transaction got intiated like tracing down the IP might prove that you actually didn't made the transaction then you can go for tether support amd ask them to freeze or refund the amount in the hacker wallet.The chance of happening is very less though but still give a try.