Problem in breathing. And it's solution.

Hello, I catch cold very frequently and when this happens, my breathing becomes very heavy. I have to put lot of force to breath and I start sweating. I have been facing this problem since last 1.5 years. After diagnosis (10 months ago) I got to know it is "initial stage of bronchitis", Thus I went through one month course of medicines and nebulisation; It was fine for a few months, but started happening again. The problem includes : Heavy forceful dry coughing with feeling of blocked air passage, also there is Humming noise in my respiratory tract while breathing in and out. Since I have dust allergy, I always cover my mouth when going out. Please let me know what would be cause of problem and it's solution.