I have shingles and I am only 14, I am taking antiviral pills and want to know how long it lasts and tips.?

I am taking acyclovir and started taking it about 3 days after the rash began to hurt, but the rash began to form 5 days ago. It is located "down their". I know for a fact it is shingles, but i want to known the stages, and how long it will laast and what stage will hurt the most. Taking into consideration i am 14, eat well, and am taking the antiviral pills, but have it in such a sensitive spot. I would also like to know if the rash is always bright red or if it changes color.thanks any tips would be appreciated.