Therapist A is a counsellor with a psychodynamic approach with experience of working with adults and young people.
Probably you should have plucked up courage and talked to your new partner before you had sex with him but it is difficult to discuss genital herpes whilst wishing to be attractive and romantic. However the conversation has to take place because, as you know, there is a risk that you could pass the virus on even though you haven’t had the symptoms or sores for some time.

With herpes, a person can "shed" the virus in their secretions and spread it to another person even when there is no sign of an active herpes outbreak. This "asymptomatic shedding" does occur, explaining how herpes is transmitted to so many unsuspecting people. People can carry the virus even without knowing they have it. There is plenty of information on line about genital herpes and you will find useful links at the end of this answer.

The difficulty for you now is how to be up front about your STD. You do need to do this so that he has a choice about whether he wishes to take the risk, but it will take some courage. I don’t think that there is a cultural problem around being honest about this kind of thing. If you are not sure of all the facts about genital herpes, check them out on the Internet. Then pick your moment. If you need to tell him in French, then make sure you know the language you need. Be positive about your relationship and its potential but tell him there is something he needs to know. Try to put it in a straight forward honest way without trying to justify yourself or somehow blame him. Then let him have his say and listen to what he feels about it. If he feels that your relationship is more than a casual one and he wants it to continue, be willing to go with him to get medical advice.

I understand that you fear rejection but trying to avoid it by not being quite honest can ultimately lead to a greater rejection.

Here are two helpful Internet links:
Therapist B is a Relate-trained counsellor with experience of working with relationship issues and is an experienced couples counsellor
I'm sorry that you are so anxious about telling your new partner, but can quite understand why you are worried as this sexual relationship is new to you.I guess it is only fair to tell him asap but there are a couple of very useful sites on www.google.co.uk which give you guidance on how to broach it as carefully & honestly as possible: www.webmd.com/genital-herpes and www.std.about.com/od/herpes

There is also a reference to it in the French Wikipedia which seems a practical approach, so hopefully your friend will take it as calmly & practically as possible. "L'herpès génital en France est très répandu et bien soigné. Beaucoup de personnes vivent avec sans altération de leur qualité de vie."

Obviously everyone's individual reaction is different but I hope that the guidelines on the following sites will help you to plan your next conversation, & that he responds sympathetically & positively.Good luck & bon courage.
Therapist C is a psychoanalytic psychotherapist with experience of working with relationship and many other issues.
I find it puzzling that you seem to partially attribute responsibility for what happened to the man with whom you are having a relationship. I wonder what makes you think that he should have asked you about sexually transmitted diseases. From what you write it sounds like you have a conflict between telling the man the truth and being afraid to tell him in case you lose him. Ultimately it is your decision as to what you do but I get the impression that your preference would be to tell him the truth.

As you rightly wrote, the stories about the French that you have heard in the US are largely myths which have most likely been fabricated by fear of the other so it is good to question them. Ultimately, you will need to listen to your own heart and do what feels right for you. I think from what you write that it would be difficult for you to be in a relationship based on deceit.