Thank you for sharing lots of details about your marriage. It's hard but it does help put things into perspective when you can sit down and read exactly what you have written about your life. It helps to realize that it's an even better idea to separate for the wellness of everyone, including each other.
You are absolutely doing the right thing by being amicable and keeping conversations short, particularly with someone who has made threats and spends more time inebriated than sober. As difficult as I am sure this is for you, you are worth more than living with someone who mistreats you, belittles you, and is physical with you. Your happiness and safety are most important.
Since you mentioned children are they being supportive? Do you have other forms of support systems?