Severe cough that lasts about a minute every 20 mins or so, resulting in thick yellow phlegm, dizziness, and pain in chest. i am having difficulty breathing, i get winded from basic tasks like walking across the room, and i feel exhausted...?

There are many possibilities for a cough with shortness of breath, the most common of which these days is Covid. However, you also could have other causes, such as influenza, asthma, pneumonia, or heart problems. If your oxygen saturation is low, or you are very short of breath, you should see your doctor or go to the emergency room ASAP. Good luck.