Breath only smells good when i am on antibiotics why is that?

Possible gum disease: You might have periodontal disease which is a chronic gum infection that is usually accompanied be bad breath and a foul taste. The antibiotics temporarily suppress the bacteria which cause this problem. See a periodontist who is a dentist specializing in treating this major cause of tooth loss.

Halitosis: Bad breath can be caused by many different factors, including sinus infections, periodontal problems, smoking, cavities, acid reflux, and your diet. Address all of these possibilities with your dentist and physician, and I'm confident that your problem will at least be minimized, and hopefully eradicated.

Halitosis: The obvious answer is that somewhere you are allowing the growth of sulfur producing bacteria, an infection. Please see your Dentist as a starting point. You may also need to see an ENT, a Periodontist, and/or a Gastroenterologist. There are mani loci of infection associated wit bad breath. Locate the infection and treat it, the bad breath will probably go away.