Have you and your husband tried marital counseling? It sounds like he has a lot of anger that he's directing at you that needs dealt with. Since he's moved out I'm guessing he's not doing very well at handling it on his own so it's time for professional help. He may only think that his contracting herpes is the issue.
Studies have consistantly shown time and time again that over 90% of those infected with hsv2 have no idea they have it until tested. If neither of you had ever had a herpes blood test before you met - there's no easy way to determine who had it first and gave it to whom or if even you both had it prior to meeting . Studies have also found that over 50% of those who think they are having a first time herpes ob - have actually been infected with the virus already and just didn't know it so even though he thinks that was his first ob - it might not have been. You can't rely on an absence of symptoms as meaning no infection ( that goes for your past partners too - they should get tested to know their status - not just assume no symptoms means no infection - hopefully your calling them and asking what you did prompted them to get type specific igg blood tests ). When your husband was diagnosed as having herpes - did he have a blood test too or just the lesion culture?
If you had never been diagnosed as having genital herpes - there's no way he can pursue legal action against you. How can he hold against you something that you had no idea you even had? He's angry and taking it out on you - because he can.
Your situation is far more common than most folks expect. Everyone thinks that if you had herpes you'd know it immediately and be plagued by frequently recurring, painful , obvious lesions when the reality is that most folks who have it - have such mild symptoms that they don't even realize they could be herpes or they are even misdiagnosed by medical professionals. I know folks who have figured out that they had hsv2 for 10, 15 or more years before they ever got an obvious symptom or they transmitted it to a partner and found out then. Unfortunately it's still not a part of routine std testing even at most clinics so folks think they are getting tested for the whole shebang when they ask for std testing and have no idea most times that they aren't getting tested for herpes.
I hope you and your husband can work thru this - herpes is far, far, far too common of a virus to let it be the reason why a marriage disolves like this