Have you seen a lawyer to give you this type of advice?
I talked to one 5 years ago when my H was involved in an EA that he was initially wanted to leave the marriage. After the OW backed off he stayed. I don't think I need legal advice unless I am more committed to divorce. Right now our situation isn't complicated. We have talked about it before but my H had a listening problem so he could always deny every hearing it. He seems willing to do whatever I want right now. The separation might be better if he thought it was his idea. He wants to keep working in the same place the OW works and I let it slide last time but I don't think so this time. He loves his job more than me so if I make him choose then it's over.
Maybe it's so hard because he is so tied into my identity. Losing him feels like cutting off my arm that keeps getting infected.