@herpesbaby, this was my experience:
Some six months in to my ME illness, I started getting oral cold sores, all the time. As in, often I'd have two, but I'd always have at least one. An infectious diseases doctor investigating my ME illness prescribed Valtrex which stopped the cold sores.
I don't know if herpes caused the ME, I think it is unlikely as I and my family had a stomach virus immediately before we became ill. And my children, also with ME, did not have such a problem with cold sores. I think it is likely that, by trying to continue to work and push myself, my body was so exhausted that it couldn't keep the herpes under control.
So, I stayed on the valtrex for 18 months or so. Every time I ran out of valtrex and didn't take it for even a day, I'd get another cold sore. But after that 18 months, I found I could stay cold sore free without it. Perhaps that was partly because I stopped trying to work and do pilates and generally just eased up on physical activity. When I reported not needing valtrex anymore to my GP she said that she found that most of her patients who took valtrex for genital herpes found that they didn't get sores after taking the anti-viral for 18 months or two years, so she wasn't surprised.
By the way, I don't think the valtrex improved my ME symptoms, although reducing the disease burden by stopping the cold sores is surely a good thing. And it was nice not to have painful sores on my lips all the time. I certainly don't think the valtrex made me worse in any way, but of course it is impossible to know how I would have been if I had not taken it.
After another two years or so, I started getting cold sores again. However, they are much less frequent. Just the other day, I felt really good and had a busy day. By the night time, I had PEM, felt as if I had been run over by a steamroller and everything ached. And a cold sore came up on my lip.
In my opinion, sorting out your genital herpes is a good idea, but I would not be at all hopeful that valtrex will fix your other symptoms.