I'm unsure if you're still dealing with the virus when it progresses that far. If you let me know I can give some good immune boosting herb, things to build up a body that has had some hard times, which allow such difficult diseases to surface.
In dealing with the nerves, you can do a simple nervine like oatstraw, avena sativa (similar to oatmeal), which you could also use as a poultice. It's super nutritive too and helps strengthen nerves. You could also eat some oatmeal for a similar affect.
My initial, strong thought was passionflower, passiflora incarnata, which is a nervine and sedative. One of my books says directly that it "can be used in part of a formula to relieve the pain of shingles."
Passionflower is a particularly gross tasting herb, so i would opt for a tincture of that.
In looking up herbs in relation to postherpetic neuralgia, livestrong suggested meadowsweet, filipendula ulmaria, which it had this to say:
"Meadowsweet is one herbal remedy that may be useful in treating postherpetic neuralgia. The primary constituents in this herb are salicylates, which are compounds that possess a chemical structure similar to aspirin. Meadowsweet has anti-inflammatory and analgesic, or pain-reducing, action. It is a plant indigenous to certain regions of Europe and Western Asia. The leaves and flower tops of the meadowsweet plant are used in herbal preparations."
You could also do something like kava kava, piper methysticum, which is quite the nerve relaxant. If you are getting it whole herb, make sure you get the inner bark. It's an analgesic sedative for relieving pain. It's a great herb for fibromyalgia, so I can see well why I would be good in your case.
If you do get the whole herb, (I can't speak for commercial tea bags), do a cold water or lukewarm water steep. And from personal experience, be ready for your mouth to go numb. Haha
Also from personal experience, kava is one of those herbs where a small percentage of people (myself included) have a slightly negative reaction in that it brought about a bit of depression for me. Use your intuition, or just be aware when you take it that it is the herb and not you.
Let me know if you want to dig in more.