Hi everyone, thanks for checking in on me healing4me.
Much of what you guys predicted has come true. He moved out of our house and in with his parents for the time being. Of course, as you all thought, this is all my fault -even though he has been the one throughout the relationship to continually threaten divorce. When I pointed this out to him he changed his tune a little bit - it became my fault for using a lawyer when, according to him, we could have handled this ourselves. He tried to blame me for him having to live with his parents, saying that living with them is a threat to his sobriety. Luckily I have done a lot of personal work around not accepting responsibility for his sobriety and I am able to not take that on. His sobriety is HIS responsibility, not mine! (Oh, and maybe if he hadn't been so irresponsible with the money he could afford to live somewhere other than his parents house!)
The biggest issue I am dealing with right now is his behavior in front of the kids. He continues to put me down and say negative things (and use an angry tone) when speaking to me in front of the kids. Luckily our interactions in front of the kids are relatively minimal. For example, this morning when he came to pick up the kids, he walked into the house and the first thing he said to me was "The house smells like *****. You really should clean it, it looks and smells terrible. It's disgusting." I have a chicken cooking in the crockpot, which is the smell he smelled and as far as the house being a mess...yes, there are toys all over the floor but the house is CLEAN - it's just not tidy. People with kids know what I'm talking about!

This comment sent me into a tailspin after they left and I doubted my ability to single parent, whether I am doing the right thing...all kinds of stuff. But then I realized this was just another way he tries to disregulate me. I need to work on not letting him affect me this way.
My 6 year old is in counseling which I'm hoping will help him process some of these issues. His therapist (my son's) met my husband once and just from that meeting was able to pick up on a lot of the narcissism issues - this was the very first meeting we had with her, I had not spoken to her previously to this about this. It amazes me that other people can see these things with my husband when I was so blind to them for so long. Yes, they are mental health professionals, but still.
I am doing my best to protect myself - documenting everything that seems important. My attorney has drafted a temporary support and custody motion which will provide me with a bit of legal security. Of course if he chooses to disregard that order nothing can really stop him so I have contingency plans in place in case he stops paying the bills (e.g. moving in with either my mom or my dad).
Thank you again - I will keep updating. I appreciate everyone's input. It really helps to have your support and insight into what might be coming. I am the type of person that likes to be prepared for any scenario and so it really helps!