hello and welcome to health care magic,
I am Dr Sriram Nathan an ENT surgeon and I will try to help you out with your problem.
At the onset let me tell you that bad breath
can have many causes of which post nasal drip
due to sinusitis
and reflux are the commonest excluding dental problems of course.
You need to consider both into your diagnosis and proceed as follows:
1. Take steam inhalation at least three times in a day for the next week with menthol
2. Take a course of antibiotic like amox-clav along with levocetrizine in consultation with your doctor.
3. take also a course of anti reflux medication
in consultation with your doctor
4. Avoid spicy, oily and high flavored food
5. If you do not get better then you must take an upper GI endoscopy along with CT PNS and get back to me of any ENT with the report
hope this helps
Dr Sriram Nathan