While what you are going through is outside of my realm of personal experience, I can say that I recognize I was fortunate in this regard. That said, I have had friendships fall apart for reasons that I did not understand, and it does feel like betrayal to have someone you trust with a part of your life become someone you never thought they'd be - either by cutting me off or by changing their behavior in ways that made me feel really uncomfortable to be around.
I do believe that if you go forward doing the next right thing that eventually the truth will out. You are a good person, and he will not be able to sustain the act forever.
I wish I could offer you some helpful advice that would make this whole nightmare go away, but I can't. I
can say that I'm so grateful to hear from you again, as a part of my was worried sick about you the longer you were away. You do not deserve this treatment from anyone... but I think you don't need any reassurances of that because you already know that.
You are a strong person. You will get through this, and your children are very fortunate to have you in their lives to stand up for them.
I am so happy that you are safe.