I am sorry to hear this. I will not hound you about holding in this lie, you've obviously understood the ramifications of waiting this long to tell her. You need to remember that when a person gets angry, male or female, they say/do things they don't necessarily mean, it's an impulse and emotions get the best at the time. Try to understand this is overwhelming for your wife. When I first told my wife, she said nearly the same things. We have a [now] three year old boy, and she was hysterical over what was going to happen, how he would take it, etc. She told me without a thought that she was going to leave if I advanced towards my transition any further than I had.
Being you is the most important thing. Children have unconditional love, not to mention you have every right regardless of outcome to be in their lives. I understand you love your wife, and perhaps she'll relax within the next few weeks, but you need to take care of your children and YOU. My wife said she'd leave, and yet here she is still - over a year later. She came to terms with my being transgender, despite how hard it is/was for her. When it came down to actually leaving, she couldn't do it because she had come to love me as a person, and not as an image [gender].
I cannot say the fate of your relationship, but please understand that she is highly confused right now and in fear. Give her space, give her what she wants. She may leave for a while, but perhaps she'll come back. Then again, she may not leave at all. She may refuse to speak to you for a while, and that's okay, let it happen. Stay strong, if not for you - for your children. Be yourself; self-happiness is most important in life. I'm here for you, PM if needed. Hang in there.