How do I fight for custody of my two children?

Hi First, if he's leaving without his children, why would you think he would try to get custody of them? Second, NY is the children's home state.  If you're concerned that he will try to commence a custody battle, my advice is to go into Family Court immediately and petition for sole custody of your kids -- and child support!   if you have his address in KY, the FC will take care of serving him through the KY courts. Third, it sounds like you should be getting a divorce from this guy right off the bat.   FC does not handle divorces -- only Supreme Court does.  You need to start a divorce action and then can consolidate any action in FC into your Supreme Court action.  You're clearly entitled to child support, i don't know about spousal support, and equitable distribution of marital assets.  Who's going to provide health insurance for your kids?   Do you have a child care person?  He has to share in those expenses. Good luck! Ilysa