I don’t see why you would be an immunocompromised and not making antibody and not having external lesions. Why would you be the one that is an exception in so many ways? I mean, if you were immunocompromised you would likely have more lesions not less.
The duration of these symptoms, the fact that you have no external symptoms, the fact that you test negative at 16 weeks all speak against herpes for me. I never say never, as you may have noticed beaus there are always exceptions, but I’m not feeling like you are one of them. I would once again encourage you to get a western blot to clarify your situation. Is there a reason you aren’t getting one?
Honestly, I don’t think I have anything to add here about you having or not having genital herpes.