it is very difficult socially. and psychologically u go through a lot of negative thoughts. ive faced the problem. The causes may be coz of numbers of disease and disorders..
In my case, doctor check up the urine, stool, blood & also tested the dental hygiene as well. but there was nothing wrong. and after all that, doctor refer for endoscopy. After endoscopy, they found active ulcer in my stomach. and im going to doctor again to show the endoscopy report.
on the similar case (very bad breath), my maternal uncle also founded with ulcer when i told my story to him.
and in conclusion, there were some of my relative who have the same problem. so i think it may be hereditary cause.
but u cant confirm your disease without visiting the doctor. so i suggest, dont hesitate to visit doctor.
i hope this also helps to u..