It’s almost impossible for any ex to take a persons house (unless maybe you own 10) after a scant 3 years of marriage. Yes our laws can be stupid, but not that stupid.
Forget the immigration fraud angle, that ship sailed long ago. Focus on getting a competent vicious divorce lawyer to contest her claims vigorously. The brief length of marriage is favorable to you.
In your next international romantic expedition, be very cunning. The user piranha abound and the prize doesn’t get more appealing than an American of some means.
Hasta la vista my friend!