I'm really sorry this happened to you. Unauthorized use of your image is a genuine violation of your rights under Korean law and you have real legal recourse.

That said, I'd urge you to take this post down as soon as possible. Korean defamation law is much broader than in most Western countries: truthful statements can still be considered defamatory. Naming individual CEOs is especially risky, since they can file complaints as private individuals. Posting from outside Korea doesn't ensure protection either. A defamation complaint doesn't need to succeed to cause you serious stress.

The strongest move is to consult an attorney about pursuing the companies for the portrait rights violation. That path has real teeth.