Suggest Treatment For Bad Breath And A Hard Bump Inside The Nose

My three year old has been having bad breath for about 6 months or more. We started brushing his teeth three times a day and still had bad breath. Tonight I noticed his snot stuck like his breath. So I looked in his nose and seen he had a yellow/green/white blob in his nose with no air coming through. I then took a Bobby pin to see if y was hard and it was it was like a rock in his nose I barely touched t and it started bleeding everywhere.