I don't know you personally, but believe me when I say that you sound nothing like a "bad father". You sound like a victim on the other side of heavy manipulation. Their "mother" is doing more of a disservice to your daughters than they may ever know. My father did this to me towards my mother and it took a long time for me to realize it. I just wish this wasn't happening to you. Unfortunately, closure isn't going to be an option for you for a long time, not until your daughters come around, and that fact right there -- not knowing whether or not you'll ever even get to see your daughters again -- is what makes it so damn awful. At least if you had a definite answer, it might ease the longing and then do something with that sliver of hope. If I'm completely off base here, let me know.
Attempting to contact them and having no response is it's own kind of torture. No longer attempting can bring a certain bittersweet ease to the pain. I can't advise you here but can simply tell you that I understand and I hope peace will come to you, along with closure from reuniting with you daughters.