First of all, take a deep breath. During this time your emotions are running wild and it sounds like you're letting them run your life. You need to take some time to calmly and rationally think about what you want. Are you ready to let go of your M and be a single parent? (I know it sounds like you are already.) Or do you want to try to make it work?
Have you read DB or DR? If not, do that first. Right now. You will see what it takes and then decide if you're up for it.
If your H is having a MLC, it may take years for him to come out of it. Are you willing to wait it out? If he is involved in EA/PA that needs to end before working on your M.
Stop focusing on your H. You cannot control his actions, you can only control your own actions. Start focusing on making yourself the best person you can be. Doing things for yourself will help you get off the emotional roller coaster.
I'm not trying to diminish or overlook the events you're posting about. I just think you need to take a step back and take a look at the big picture. Once you have an idea of what you want and are familiar with DB practices we can help you through it.
Also, I don't remember if anyone has said this, but continue to read and post on other people's threads. You'll get familiar with how others are handling their sitchs and they'll get to know you and come here to check in on you.
If you love somebody, set them free. http://tinyurl.com/2empx2g