Bulletnurse,
One of the first things they ever told me here was the most powerful: Stop and breathe.
You can't solve years' worth of problems overnight. You can't break the mental habit of seeing him and reacting to him overnight. It does take time.
I'm so glad that you and the kids are safe. He has chosen a road for himself that is, as my brother says, "No kinda life for someone as nice as you." You may care for him or, more likely, have really nice memories that you're clinging to of him, but the person he has now become again is toxic to you. Selling marijuana in California isn't just illegal -- it's dangerous. A so-called "medical marijuana" grower here in my city was killed not too long ago by intruders who were after his crop. You do NOT want to be mixed up with that dangerous, sick (and lazy) way of making a living. The fact that he's probably doing meth, that he is abusive, that he's got a penchant for young girls.......this is "no kinda life for someone as nice as you." That's not love. And love is what you deserve.
But, back to the beginning: You can't solve it all at once. Find a meeting, or try several until you find one that seems like a good fit (they won't all be).
Perhaps try some timed-release melatonin for sleep. It helped me, and continues to help me in the times when I sit there staring at the ceiling at 4am. Getting better sleep will help you to keep your mind clear and calm.
Take extra-special care of yourself and your kids. Do as much together as you can -- stay busy with stuff that really lights you (and them) up. Your best chance to keep them from turning out like him is to 1) Keep them away from him so they can't model his behavior, and 2) Talk to them, calmly and openly, and ask them questions about what they've been through. Some of the moms here have taken some really helpful counseling sessions to help their kids process the lousy experiences dealt out by addicts.
Breathe. Take one small, baby-step in the right direction every day. Keep protecting yourself and your kids. Be realistic about him; he can only hurt your chances at happiness at this stage.
And keep posting. There's an astonishing amount of support here, and this place saved my life.
Hugs to you!!!
You're going to be okay, honest you are.
GL