What can be my remedy to have custody of my children?

My problem is regarding about my ex boyfriend, we've been together for almost 6 years we broke up and we do have 2 kids, 1 girl,1 boy. We don’t go to court for child custody. We agree that we just going to decide it in our own way. 50/50. Last year I went to the Philippines to visit my husband for 9 months but before I went, I ask permission on him, that I will visit my husband there because I hardly saw him, I even beg him that I want to take the kids with me for vacation, or one of them will go with me. He refused, so I went to the Philippines. 1 month later he told me he went to the court for child custody, I was shocked ( I don’t know if that one is true) while I’m in the Philippines, I keep calling him that I want to talk to the kids, I want to say hi, and Skype with the kids, he said no your just hurting them, I said that’s why I want to talk to them every day in Skype so that I keep communicating with them, even my baby girl birthday he won’t let me talk to her because his girl friend will get mad if I contact him. And now I’m back here in Arizona, he keep making an excuse, I want to see the kids; he won’t even tell me where they live at. I really want some help, because I really don’t know what to do, I really miss them so bad.