I've followed your story for some time now. Here's how I see it ...
You are a victim of abuse and you hung onto the hope that your husband would all of a sudden deal with his nasty habits in a constructive way.
I think you've hit rock bottom because deep down, you realize that he's not like you, he's not truly trying to heal himself and your relationship. It's very difficult to admit that the person you gave your love and trust to is a cold-hearted liar. You need to understand that it's very likely that he doesn't "have the parts" to go through the process you described in your opening post. From the way you described his mother, it's highly likely that he was conditioned to be this way from birth. Ask yourself, would he have gone for counselling if you hadn't confronted him with what he was doing?
You can't create a peaceful home when you're living in a war zone and the other person wants to maintain the status quo. In general, people only change when they have to ... when they would otherwise have too much to lose.
So you'll need to either accept that he has these addictions (whether or not you knew about them before now), and live with them, or possibly make other choices for your life. Since he's taking you to court, it may or may not be too late to have a workable relationship. How many times do we see politicians' wives with those frozen smiles, standing by their man after his adulterous affairs have been exposed?
Do you have a Women's Shelter close by? I strongly suggest that you find out asap. Deep down, you KNOW what you need to do ...
I'm not a religious person but I do believe that each of us has within us a power far greater than we realize. My suggestion is to gather all the evidence you have of his activities and have them ready to present in a factual way when he takes you to court. Keep it in a safe deposit box if you have to.
I too was in an abusive relationship and I finally broke the pattern and walked away after 20+ years of trying to get him to treat both me and our children decently.
You are right. The only one you can change is yourself. His taking you to court is payback for exposing his activities which he hid from you so long.
You have my heartfelt thoughts wishing you hope, strength, and the ability to forgive yourself.