There are multiple issues here that you are trying to have addressed. Given the circumstances and the complexities, I highly recommend you seek the advice of a local attorney that practices in family law. Many of us give short free or low cost consultations where we can review all of your options with you.
It is good that you now know where he is located. If you have not yet done so, you should immediately file for support. A court can impute income to him if he is voluntarily unemployed or underemployed. Given he made a six figure income before, there is a lot of opportunity for the court to do so. In addition, if the woman he is living with thinks he's worth paying for so he doesn't go to jail for contempt, you may find that some support starts.
You should also be exploring avenues of divorce.
Please note that this response is based upon the limited information available in the question. In addition, it is not intended to create an attorney/client relationship and is offered only as general information and not as legal advice.
I agree with Ms. Allen. You should retain the services of a local divorce lawyer and have him served with a summons for divorce requesting everything you are entitled to, including spousal support and child support. Good luck.