hey you - listen first of all relax - there IS a cure - it ISN'T in your genes. Bad breath is a symptom of something NOT a disease!
Okay - there are THREE possibilities
1) That you have sinus problems
2) that you have teeth problems
3) that you have digestive problems
Its more then likely to be digestive problems (especially if your mother has it as you probably have a similar diet!)
To ask you a sensitive problem - do you have bowel problems? Do you go AT LEAST once a day?
My brother had you EXACT problem (plus he had chronic diarreah and constipation -not at the same time though!) and all he did to get rid of it was eat a HELL of a lot of fibre. He had porridge for breakfast, rice and vegetables for lunch or dinner, chickpeas, lots of fruit and veg and his bb disapeared within 2 weeks! It wasn't expensive, it wasn't a miracle - basically he must have been putryfying inside.
Try going vegan for a bit - i.e cut out meat and dairy as they rot and smell!
Also do you get indigestion? Reflux? All associated with digestion and should get ironed out when you change your diet!
To check your teeth, go to the dentist and say your gums are bleeding and you have a bad taste in your mouth (less embarrassing then saying bb) and he'll immediately check for gum disease which could be a cause.
For the sinus ones - do you feel stuff running down the back of your throat?
Any questions post them up! My bro thought it must be a curse - but it was just logic - if you put food in a bin and leave it there when you take the lid off (i.e. open your mouth - it smells!!)
I did a bit of research on movicol that was a laxitive as a friend from a different forum was interested - but she too just changed her diet and didn't have any problem with her bowels.
GOOD LUCK !