Therapist A is a counsellor and life coach with experience of working with alcohol and addiction issues as well as with eating disorders.
Considering how upsetting this has been to both of you, it might be a good idea to see an English speaking doctor together so that you can be reassured and if, after that, there are still issues, then some couples counselling might be helpful. Here is some information about herpes: CLICK HERE

Therapist B is a Relate-trained counsellor with experience of working with relationship issues and is an experienced couples counsellor
I'm sorry to hear about your sexual health dilemma,& indeed it sounds even more complicated by an apparent lack of trust between you, in that you clearly think that your husband has had sex with someone else & he says he thinks the same about you? It must be creating a very difficult atmosphere between you ,& until / unless one of you is able to work out honestly what might have happened, it feels as though you both have a distressing stand-off situation, which is threatening your marriage.

One way or another I'm very sorry that you are the one who is infected, & hope that you will get as much help & information about what to do next from the many web sites on www.google.co.uk or on www.angloinfo.com  for more local info on France/health/English speaking doctors etc.

However, if you also look on the following web site :-
International Herpes Alliance, Genital Herpes, Herpes, Patient Support
The IHA is a global association of patient support organizations and health professionals concerned about genital herpes - information: regional support ... www.herpesalliance.org 

it does seem to confirm that this is a virus that is sexually transmitted, but it also says that :-
"Genital herpes is passed from person to person through direct skin-to-skin, genital-to-genital or mouth-to-genital contact. Therefore, it is most commonly transmitted during intimate sexual contact. Many people first discover they have the infection at some time during the course of a long-term, monogamous relationship. Evidence of infection in a long-term relationship does not necessarily indicate that there have been other, recent sexual partners."

I don't know how long you've been together/married, but do you think it is something that could have lain dormant from before the time you met each other? I realise that it doesn't help your current health situation, but if you could try to discuss this information above with your husband it might clear up your anxiety about the potential unfaithfulness which is hurting both of you at the moment?

If on the other hand you genuinely suspect that your husband is lying, then maybe you will need some counselling help with your relationship,& could try the
counsellors section to see if there is a counsellor nearby who would be able to help you with some further personal counselling.
Therapist C is a psychoanalytic psychotherapist with experience of working with relationship and many other issues.

Therapist C is currently away and will answer soon