Herpes or genital shingles

I am 36 and when I was 19, I was diagnosed with genital herpes. At the time I had only had one sexual partner who was apparently given the all clear for the disease. I could not understand how this could be the case. I had many outbreaks. Then when I reached my 30's I started to get a strange rash on my backside. This would be preceded by a terrible pain in my leg and ankle. I was finally diagnosed with shingles. I have outbreaks of shingles when I am stressed, although I can go through stages of not getting the condition. Is there any relation to the two conditions? Or is that I may have been missdiagnosed for one or other of the conditions?