Ask your doctor to check your thyroid and your immune system. As before i was diagnosed i suffered with lots of colds and coughs through out the year. Your immune system may be low.
probably your suffering from cold allergy.you may experience running nose,stuffed nose ,nasal blockade.cetrizine may offer you symptomatic relief.permanent relief is quite difficult.take multivitamin tab with zinc.
It seems that your immune system is weak ... Try to get multivitamins, extra Vitamin C , eat lots of yogurt , garlic and onion in your diet ( or garlic extract pills ) . Try homeopathy and homeopathic remedies before you even get sick ! Preventing is sometimes easier and wiser then treating !
If nothing works you might want to have a complete check up to see maybe there is an underline issue that triggers all this !!
Good luck !
All the best,