Do not use sensodyne. Or an other type of desenitizing tooth paste .
Cause of your teeth sensitivity are most likely calculus formation. If the yellowish discoloration is evident since short period of time.
mouthwash: hexidine once a day for 10 days, after meal. followed by once in every 2 days.
Next Steps
undergo scaling.
Health Tips
Luke warm salt water gargle.
Follow proper brushing technique for cleaning all surfaces of teeth.
tongue cleaning regularly with plastic tongue scraper.