I'd suggest you take immediate steps to protect yourself financially. If nothing else, DOCUMENT everything he's doing with the family's resources. The family court won't look too kindly on squandering marital assets.
Tell your husband that there are only two things to talk about -- your marital relationship, or the end of it. Tell him that if it's the former, you won't discuss it so long as there's a third person in it. And if it's the latter, that you've re-contacted an attorney to discuss your options, and that any M or S talk is "legal", and best handled by the attorneys.
Your husband is very stubborn, and his affair seems very entrenched. You have, in fact, already done most of the things that I would have recommended to you. Time to put on your game face, and kick it up a notch. Are you up for it?
