You never have full custody, unless the mother is actually abusing or endangering the children, and even then she will likely get supervised visitation. I don't know what your current situation is, and certainly empathize with your desire to have your own children, I have gone through this twice and wound up with primary residency both times. Primary thing to keep in mind is that the people making the decisions do not know you or your ex, and are trained to assume that fault, such as it is, is a 50/50 proposition where there is no hard evidence otherwise. Keep control over yourself and hope you can get her to show whatever flaws she has of her own accord.