Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain 
bad breath also known as 
Halitosis can occur due to a number of causes like 
poor 
oral hygiene, oral and dental infections, tonsil stones or tonsilloliths,
post nasal drip, 
sinusitis, 
acid reflux,respiratory infections, diabetes etc..
You should consult an Oral Physician or an Otolaryngologist and get evaluated and a thorough 
clinical evaluation and investigations depending upon suspected cause can help in diagnosis..
Treatment of underlying cause will relieve the symptoms..
As of now you should start gargling with a flavoured mouthwash twice a day..
You should chew flavored sugarfree chewing gum..
Do warm saline gargles twice a day..
Limit the intake of high aroma foods like onion and garlic..
Drink plenty of water and maintain a good oral hygiene..
Hope this helps..
Regards..