What Causes Difficulty Breathing While Coughing?

Good day.. This is my problem.. Everytime I cough, i find it difficult to breathe, and there is a wheezing sound.. And i tend to vomit, but there is nothing comes out, only a loud sound..and there is no phlegm, or maybe very few, i only spit out thick, whitish saliva.. And because of my hard coughing, i now feel some pain on right chest.. I have been experiencing this for almost three weeks. Thank you for your help