How to stop this severe coughing and sore throat?

First, you need to have your cough and sore throat diagnosed. There are many reasons for a chronic cough including acute or chronic bronchitis, bronchospasm from any etiology, GERD, post-nasal drip, etc. The sore throat could be due to the cough or some other reason. So, you should call your doctor for diagnosis/treatment. If you smoke, it is a great time to quit-your doctor can help you quit!