Ur cavity looks small to medium and the exact extent of decay can be identified in an iopar(x-ray). If it's a small cavity then there is no need of any anesthesia injection...and if the cavity is little big u might have some sensitivity. If that sensitivity is very severe for u only then we dentists vl suggest u to take anesthesia injection to relieve u from pain....so don't panic or don't get anxious
Next Steps
consult a dentist near by and take an iopar(x-ray), then seek advice of the dentist depending on cavity extent
Health Tips
avoid overthinking about it and go to dentist with a positive mindset....u vl definitely get painless treatment