"The truth is, he chose the situation that he is in".
Lillamy hit the nail on the head. Guilt is a terrible feeling. I am in a situation where I feel the trigger of guilt as well. It helps me a lot to remind myself that "he" made the choices that created this situation. Yesterday, when I turned it over to God I realized that a lot of my guilt feelings were coming from my feelings that I caused it, could control it, or could cure it. None of that is true. Your husband is dealing with the consequences of his actions.
The only thing that you can do is take care of you and your children and decide what is best for ya'll. Seeking legal advice and really thinking through your options is get advice.
I hope you keep on posting about this if you have feelings of guilt. I know that my feelings come and go. Last night I was doubled over in tears about lots of guilt - but then this morning I have a little more clarity.
Hugs....