If cavity is hurting it means the infection has spread to the tooth pulp and needs Root Canal Treatment (RCT). RCTs can be done in single sittings also, so you can get it done while on travel also.
Next Steps
Look for an "Endodontist" (RCT expert) on Practo in whichever area you are at.
Health Tips
In case you don't have any allergies, you can take the following medicines.
Rx -
*Tab Augmentin 625mg* {2 times a day}
*Tab Ketorol DT* {3 times a day or whenever it pains} - Dissolve in half a glass of water and drink
*Tab Pan 40* {2 times a day, half an hour before food}