Funny story: One time my husband answered the phone at dinner time and then said, "No thank you," and hung up the phone in disgust. I asked if it was a telephone salesperson. He said "no, it was some neighbourhood church inviting him to their services." Then he said how annoying it was to interrupt people's dinner with that crap. I nodded sympathetically, and agreed, "yes, it is very annoying when people call or show up at your home uninvited to talk about their religion". My son burst out laughing, and my husband just said sarcastically, "very funny." JWs seem especially incapable of analyzing a situation outside of their own narrow frame of reference.
Okay, that's funny!
I'm going to call a spade a spade here, with apologies in advance if it's hurtful to you.
I believe that you love your wife very much. However, if she has pulled out the divorce card so soon, then only one of two things can be true - and they overlap a bit. Either she doesn't love you as much as you believe, or she is a manipulative woman.
Disregard the fact that in Planet JW she is only allowed to divorce you if you have sex with someone else. You no longer play by their rules. I support previous advice to CALL HER BLUFF. Next time she mentions divorce, tell her how sad that makes you, but initiate a conversation about the details: the date on which she would like to start action, which lawyer she will be using, access to the children, and so on.
Once the divorce ball is in her court she may be shaken by the reality and practicalities and pure enormity of what she is proposing.
It may shock her into realizing that she doesn't want to lose you, or shake her out of using this manipulative threat. If it does neither, then previous advice to start consulting with multiple lawyers is excellent.