Hello, portlandiagirl, and welcome! I have not had this experience, but maybe someone will come along eventually you will. Remember that folks with this disorder are Johnny one notes: "mi, mi, mi," (me, me, me). So you can expect him to likely be angry that you are making the first move. Maybe even a "how dare you want to divorce ME" attitude. And blame you for everything. He will likely make things difficult for you, perhaps fighting the divorce, but I am not sure. And, of course, trying to keep you from getting anything decent in the settlement.
Again, I am guessing, though, since I have not experienced this situation. Best wishes, dear one. Hold firm and protect yourself and your children.
Please keep us informed.