For a wet cough with thick sputum, you should take an expectorant like Guaifenesin. This helps thin and loosen the mucus, making it easier to cough up. Avoid taking strong cough suppressants, as clearing the mucus from your airways is important. For nighttime relief, try elevating your head with extra pillows, using a cool-mist humidifier, and drinking warm fluids before bed. Since your cough is severe and continuous, please consult a doctor to rule out bacterial infections or bronchitis, especially if you develop a fever, chest pain, or shortness of breath.