IMO your wife is out of control and in deep emotional turmoil. She is also an alcoholic , who tried to take her life. She needs professional help! Alcohol is but a symptom of a much bigger problem. That doesn't mean you have to put up with the violence. No one should have to live like that. I guess, I would get a court order and have her removed from the home. She will not be able to abuse anyone but herself. Unless she decides to get help, I have a feeling things will get a lot worse for her. She's on her way to "rock bottom".
You are NOT a coward. You love her and are trying to "help". Unfortunately, you will fail. She has to help herself. Hopefully, if your not ready to go the legal route , you will look into al anon. You will gain awareness and hopefully learn some tools necessary for you to find some peace.
Best Wishes to You