Halitosis may be because of many reasons .... In your case it could be because of stomach and mouth ulcers ...due to mental stress(due 2 work,family pressure, oily & spicy & non veg food, ESPECIALLY smoking)
Next Steps
Stop smoking n have bland diet for a month also have .... Badam daily morning and night 4-8 heals ulcers
Health Tips
Also gargle moutt with salt water after brushing Ur teeth in d morning n night b4 sleep .....n after every meal