I am so sorry you need to be here, but glad you found us. The pain of betrayal is so intense. For those that have not been betrayed, I do not think they understand it. There is a wonderful amount of support on this site and I hope you us it as you work through the problems you have.
I think you are making some very wise choices for you and your children now. On this thread, is information on the 180. That information can help YOU as you are still around him some and will help your healing. Hopefully, you can get away from him quickly. Remember, 180 is for you...not a punishment to him.
I also encourage you to see an attorney. If he has done this before, he has learned lessons from his previous divorce. Get one quick so you are not on the losing end. Also, you need to make an appointment to be tested for STD's. It is embarrassing ,but necessary. You do not know what else he has been doing.
Take care of yourself, eat when you can, drink plenty of water and take care of your children. Remember you do not have to make quick decisions on anything right now.