A few days ago I woke up and my own breath was just awful. I did my regular routine and it seemed to help, but when I would yawn or breathe too hard it tasted SO bad! It's been 3 days now and it won't go away. Everyday I brush my teeth and tongue, use a whitening paste, and gargle with mouthwash. I've never had bad breathe before really and never this bad, what could it be? How do I fix this?