Very sorry you had to go through that! Next time OM lays hands on you then call the police, that is illegal and unacceptable.
Contact a lawyer ASAP. If your W is ignoring you she is basically preventing you from seeing the kids and that is not acceptable. You need to get a visitation agreement in place.
Also, at least for a while you may want to record every interaction you have with W, it may make good evidence if she fights you on a custody agreement.
