Instead of writing your own answer, you should retain an attorney to handle this case for you. Your children are far too valuable for you to risk doing something wrong. And, although you can certainly write a simple answer or "response" to each allegation in the motion or petition filed, there are many other things that you need to know to file a proper response to protect all your rights.
You indicate that you had a free consultation with a lawyer and that lawyer indicated the court does not have jurisdiction. That makes it all the more important that you hire a qualified lawyer to handle the case for you. Family law is not easy. And there are too many things that can happen if you don't know what to do or how to do it. There's an old saying: "A man who handles his own court case has a fool for a lawyer."
This response does not constitute legal advice and does not create an attorney-client relationship. I am licensed to practice only in Kansas. Seek legal advice from an attorney in your state or the state in which your legal claim exists.