After drillling, your tooth may be sensitive for a few days, especially if it was a deep filling but this should settle. Why did you need the filling? Was it a replacement for a previous fractured filling or did the tooth have decay (caries). Sometimes decay has to travel pretty far into a tooth before you experience symptoms so if your decay was shallow, you probably would not feel any pain beforehand. However, the tooth still needs cleansing to stop the decay spreading and it will be sore for a while. If the decay has irreversibly damaged the nerve (pulp), despite thorough cleansing, the nerve will need to be removed, and root canal treatment or tooth removal will be indicated. You will know this is happening as the tooth will be extremely painful with hot/cold and become tender to bite on. Episodes of throbbing pain will come spontaneously, often lasting hours with no relief from medication. You will need to see your dentist urgently if it gets this bad!! However, give it a few days, even a week, and see how it goes, taking painkillers as necessary. Teeth can be sensitive for an awfully long time after dental work but if the pain improves, no matter how slowly, this is usually a good sign. Hope this helps.
I am a dental surgeon