Another thing we have noticed is that he does not remember things. ANd in the last few months, he will tell the kids that he will be here at 1PM to pick them up, and he does not show up until two hours later!!!
Being on time is one of my peeves but I have noticed the mood swings and the forgetfulness. Not sure if it is just alcohol or a combo of that and drugs.
Believe it or not, someday "he" will not be a topic of conversation for you!
Try a couple of things - start writing a gratitude list. Put on it everything you can think of, from being alive to having a roof over your head, to having food on the table (and a good Greek marinade recipe), to clothes on your back and some pennies in your purse.
Just keep going and add to it throughout the day or anytime something comes to mind. You'll see that it will multiply as you go along.
2nd, have a touchstone - mine is the 23rd Psalm. Anything you can say to yourself automatically and feel calm.
3rd, keep your shoes under your bed. That way, you have to get down on your knees to get them to put them on for the day ahead. While there, think about the first two items. And listen to the still, small voice.