How long Will my Shingles Last for?

I'm 14 years old and i have shingles all over my left thigh and starting to spread down my left leg. I mean it's very rare for children to have this, but i do and the pain is very unbearable and i'm basically limping with pain on that leg. How long would it take for the red dots to go away, and more importantly the pain? I first got shingles probably on Saturday, 1/23/10. the pain started about Monday, 1/25/10. I saw a doctor and he prescribed me medicine, but he said the medicine wouldn't work as effectively since i saw him a little late. He said narcotics would be an option to get rid of the pain.