Ur symptoms suggest coccydynia..which is essentially inflammation of coccyx bone and its bursa due to frictional injury.
Next Steps
1. Do sitz bath.(sit in a tub of hot water with some drops of dettol, affected portion should be dipped in hot water)
2. Sit on a soft pillow.
3. Take medications like Enzomac Forte twice daily for 10 days.
Health Tips
Relief takes 2-3 weeks. Don't sit on hard surface. Avoiding riding bike on rough surfaces.