I am sorry you are going through this. You can sometimes 'forgive' but can often never 'forget' the hurtful things and sometimes you just have to break away for your own sanity. The 'capable of murder' threats worry me. I had those back in april but thankfully they have now stopped, but I have had trouble moving on.
I agree with the other posts -seek out a good therapist.
Once the line is crossed, it is very difficult to forgive and move on even if she does stop or cut down drinking. You are not responsible for her.
Why is it so easy to give advice and not take it?
Do take care and best of luck.