Worry - Tooth Sensitivity

Lately, whenever I eat cold food or brush my teeth

My tooth is extremely sore, to the point that it even feels painful.

I brush well and have no cavities... I wonder why this is happening...

I'm afraid to go to the dentist... Someone told me that.

Consistent use of dental floss can help reduce tooth sensitivity.

They said they could eliminate it... Is it really true?

Has anyone overcome tooth sensitivity?