Sensitivity to sweet, hot or cold foods, or pain when chewing. Go for consultation.doctor will advice you IOPA X RAY then will do filling or rct according to finding.

Hi sir... you history seems it may be cavity.. Pain is due to the cavity which reaches your nerve layer.... First and foremost you need to take X_ray(IOPA) of involved tooth done to diagnose the depth of cavity.... If the cavity reaches nerve layer You need to go for ROOT CANAL TREATMENT of cavitated tooth If the cavity doent reach your inner nerve layer then simple filling is enough ... The sour smell may be due to **Food accumalation in the cavity which leads to sour smell **Generalized soft and hard deposits(plaque and calculus) in teeth that needs to be cleaned(scaling)...

Visit an Endodontist for proper treatment

Hloo Sir If you tooth is sensitive to cold and hot and also to sweet you need to go for x ray and then see whether caries have reached pulp tissue and if it is so then you need to go for rct and then crown You can also practo consult us Regards