Pratija, your best practical option is to search for an American advocate online who specializes in civil tort and family law. Most American advocates, unlike in India, specialize in some field of law. Most law firms have many advocates, each specializing in some area of law. Try to find a law firm which has an office in the same state as your husband. This is important for two reasons. First, of course is the convenience factor. Second, and more importantly, in America law of tort as well as family law are state laws. They vary across states.
The next obvious question will be legal fees. Right? Do not worry. In America, it is fairly common to have contingency fee agreements. The advocate/law-firm retains a certain percentage, usually around 30% of whatever he is going to recover from your adversary. This is prohibited by the bar council in India but in America it is not only legal but is a widely accepted practice. Contingency fee agreements do not usually cover expenses but in your case you can try and explain the situation and see if you can have them take care of it.
You can recover primarily on the basis of fraud and emotional distress. The elements of fraud and emotional distress will be easier to establish in your case. In America, for both these legal basis, you get not only compensatory award but also punitive damages which can be substantial. Alimony will be pittance in comparison! Your American lawyer will probably identify other basis on which you can sue him.
I am fairly familiar with American legal system and the court systems and am a long-time resident here and can assure you that the discussion on extradition and any remedies in India thereafter are not worth pursuing.