I know how you feel. Unfortunately, I've had this damn thing happen to me 5 times within the last 2 years and i'm only 24!
My theory is that I really believe that allergies have a lot to do with it for young adults. Within the last two years i've started to develop allergy symptoms which I never had before...and as you know shingles usually appear when your immune system is low..also allergies weakens the immune system..so I put one and one together.
Besides this whole shingles thing i'm usually healthy.. so it still remains a mystery.
I don't treat my outbreaks with any medication because I don't have a really severe case of it when it does reappear.
Anyway, all i can say is ...don't worry!.. I hope all gets better for you. The only fear I have about this is that I don't want it to reappear in another spot..if it remains in the same spot and doesn't get larger i'll be ok with that!