I COUGH ALL THE TIME AND IT FEELS LIKE MUCOUS IS STUCK IN MY CHEST AND THROAT. Sometimes I wake out of sleep gasping for air and coughing?

Evening cough. your symptoms could be from post nasal discharge but also could be from a cardiac or pulmonary cause i would suggest that you begin with your primary doctor for a full evaluation.
Asthma. My first thought would be bronchospasm and excess mucous with plugging - this is a manifestation of asthma. If you're not known to have asthma, you need to be tested for it. That might be as simple as listening with a stethoscope or may require breathing tests. If you smoke, you must stop immediately and for good. Allergies are another possible trigger for asthma. There are many good treatments.