So to your original problem,Post Nasal Drip And Excess Mucus – It WILL Make Your Breath Worse!
Research has proven that the anaerobic bacteria that cause bad breath use the proteins found in post nasal drip as a food source!
If you suffer from excess mucus, sinus congestion and post nasal drip there are essentially only a few different routes that you can take:

1. Use medication and or drugs to dry up the sinuses and prevent mucus buildup – all the while being careful to avoid a dry mouth, a likely side-effect of virtually all antihistamines. Dry mouth is the most common initiator of bad breath because it mimics an anaerobic environment, perfect for the bacteria to pump out Volatile Sulfur Compounds. You should be careful about using any antihistamine frequently – many are habit forming!

2. Use TheraBreath Nasal Sinus Formula. By squeezing 3-4 drops into each nostril (and then lightly inhaling to move the potent formula through the sinuses) twice daily, most people can finally experience that fresh breath and taste feeling by eliminating the production of sulfur compounds created by the reaction of mucus and the anaerobic sulfur producing bacteria.

3. For chronic sinus problems, many patients will find relief by using the Hydropulse® (an amazingly effective Nasal-Sinus Irrigator, designed by an Ear Nose & Throat specialist) to flush the sinuses. (It works even better when you add just 2-3 drops of AktivOxigen serum into the trough before each use.)

4. Minimize the amount of post-nasal drip in your throat and sinuses, and eliminate the #1 side effect of excess mucus, bad breath, by using oxygenating oral care products, such as TheraBreath, TheraBreath PLUS, AktivOxigen, PerioTherapy, and TheraBrite. Medication and drugs may help prevent post-nasal drip, but at what cost?

There are dozens of different over-the counter nasal decongestants and antihistamines that you can use to help relieve congestion and dry up excess mucus. Some of them do what their manufacturers claim they can do, but most of them perform the job too well! They create an extremely dry mouth, which exacerbates bad breath. Even in cases where the dry mouth side effect is minimal, when you stop taking that medication, the problem often comes back even worse! This is because in some cases your body will actually develop a resistance to any antihistamines or nasal decongestants, especially nasal sprays (be careful, because many sprays are habit forming, but NOT TheraBreath formulas)!

I have a link for you here which will help you I hope http://www.cure4-halitosis.com