Although not an alcoholic (that I know of anyway) my brother was involved with someone who had an undiagnosed mental illness. Things also went bad and she did all sorts of similar things like abusive messages, filing reports of abuse against her and their kids. He had to protect himself because the system usually favours mother. He kept copies of any messages, and every time there was an argument or incident HE would file a police report so it would be on record. Eventually she got the better of herself because her track record of passing bad cheques, fraud and other things became quite apparent, so that every time my brother was brought before a judge, her record spoke for her and they'd dismiss any nonsense against him. He eventually won custody and she has been in jail off and on for her petty crimes.
Protect yourself with gathering any evidence like voicemails/emails etc and please do go to the police to tell your side as the other posters suggest. Pre-empting her can make a difference, because even if this blows over, you cannot guarantee that once you're out and you have your stuff or however it ends, she won't try to pursue further. My brother, even after the divorce, suffered for years with crazy attempts to reconcile. (and when he wouldn't she would do something like cut his utilities, tow his car, stalk him)