Hello ma'am Big cavity means your tooth have to undergo root canal treatment.if x-ray would have done before doc could have predicted before. Go for rct or second opinion.why wasting time.rct will give you relief in single sitting. It cost you 1500 to 4000.depends on the condition of tooth and procedures u go for. I hope I was helpful and will be seek further to help you at my clinic.

Visit a dentist asap as the medicines will not give you permanent relief for the pain..A deep cavity basically indicates a need for Root canal treatment in your particular tooth if it is paining even..Get the further treatment started alongwith the prescription and get a confirmation x ray for accurate diagnosis.

You require a proper clinical checkup. However your symptoms mostly suggest the necessity of a RCT. If there's any filling done.... Get it removed. It might give you relief