So if they aren't seeing herpes, what are they seeing? What are you seeing?
Has anyone cultured them to make sure it's actually herpes and not something else? They can do a PCR swab of the area(s) even if you aren't getting blisters. PCR swabbing is very sensitive, so if you have symptoms, it should find the virus.
Or do you mean that doctors don't typically see herpes on the gums, so they don't know how to treat it? There's something called herpetic gingivostomatitis, which is essentially a herpes infection on the gums.
It's more common to have it with your primary outbreak, and in children, but if you are immunocompromised, it's not uncommon to get recurrences of it. How bad is your iron deficiency? Do the shots bring you to within normal ranges? Are you considered immunocompromised?
There is another antiviral called Famvir that some with hsv1 respond better to. You might try that. If you are someone who gets periods, you might try tracking your outbreaks around your cycle, and see if you up your Valtrex a few days before your period helps prevent them. Maybe a food or drink is triggering them.
Lysine hasn't been proven to do much, though some swear by it. If it isn't working for you, save your money. If you try Famvir, it's probably more expensive, so put your money towards that.