Hello and welcome to e health forum.
It is usual for the rash to worsen sometimes before it gets better.
Though antiviral medications are given to control the symptoms , they need to be taken for a few days before the effects are evident. The symptoms may not improve on the first day of treatment.
But narcotics and creams provided do help to reduce the symptoms to some extent.
Shingles or Herpes zoster usually clears in 2 to 3 weeks and rarely recurs. If the virus affects the nerves that control movement (the motor nerves), you may have temporary or permanent weakness or paralysis.
Sometimes, the pain in the area where the shingles occurred may last from months to years.