Welcome to NeuroTalk.

How long have you been on Diltiazem? And what dose?
I ask because this drug can upset calcium metabolism, and give leg cramping. I take this drug, and when I don't eat calcium rich foods I get alot of muscle problems with it. Also swollen feet sometimes and that is at the lower end of the dosing range.

So I would make sure you are getting daily calcium and also balancing it with magnesium which will also reduce cramping.
Low calcium will cause paresthesias, as a sign. I can get leg cramps from diltiazem. I take 1000mg of calcium when this happens.

How much Vit D are you taking? Did you get tested first? Vit D will improve calcium absorption from food.

I'll be interested if the antiviral works for you. That is very perceptive of your doctor! Herpes Zoster can remain active and cause alot of pain/grief. Another aid for this is l-lysine. Improving the ratio of lysine to arginine, can help keep the Zoster virus dormant. You could try adding about 1 gram a day of l-lysine as well.

We have another poster here, Ivpound, who was on Coumadin and had alot of burning. At the time I searched the literature for him and could not find a published connection to "burning", but I wonder if that is a factor for you too? He tested low in Vitamin B6 as well. You never know with drugs, as there can be unusual side effects that are unique to small numbers of people and hard to trace.