Call or visit your nearest Justice Court and ask them about getting an "Order of Protection" against her. This will prohit her from coming to your residence or place of work or contacting you in any way, under penalty of Contempt of Court. The Court and its staff will give you the appropriate form and you can fill it out yourself. She will be served with a copy and a short hearing will be set. She may, or may not show up. It is fairly informal though emotions may run high. Best of luck.