Get a complete scaling done by your dentist and start with warm saline rinses and gargles. This will definately solve your problem.

There are various causes for mouth malodor . It can be from the mouth or from the nose , throat and then further down from the food pipe and the rest of the digestive system . If it is from mouth (oral cause) it is easy to treat . You can visit a dentist for a routine dental examination to find out if bad odor is originating from mouth . Dentist will check for presence of food lodgment between your teeth, impacted /partially erupted wisdom teeth, decayed teeth , gum infection called gingivitis/periodontitis , even dry mouth as all these are common causes for bad breath . But if it is not from mouth one may have other extra oral causes such as constipation, acid reflux disease or sinusitis , respiratory infections , even prolonged starving etc . So get a dental check up to see if is of dental origin. If your bad breath doesn't reduce after the dental treatment consult a physician.

Mints do not remove bad breath.... they just cover it for some time..... Nothing much can be done for correction of the size and shape of the tonsils at your age.... Regular rinsing of the mouth and gargling after meals is the only conservative method.... I would suggest a proper clinical examination by a dentist to evaluate the presence of deposits below the gums..... Also you should clean your tongue with your toothbrush after you brush your teeth.....