HI. This is most probably due to Granular Pharyngitis or Tonsillitis that you are getting so much pain. Do not take codeine so much as it can cause constipation. You have to take a course of an antibiotic and anti-inflammatory medicines to get a cure, only symptomatic treatment will not help. Consult an ENT Surgeon , get examined, get blood and throat culture done and get a prescription for proper treatment .