Batchel, with regard to your post wondering why, whenever you get a glimpse of what normal is like: night out with friends, drama free time with kids, interest from a guy, you feel the need to turn back to the unhealthy relationship.
You were together a long time. You had children together. You have been on your own for about a month.
I think that it takes time to fit into the new normal.
Keep what you want squarely in front of you, and you will be okay.
Peace.