For your dry cough, an over-the-counter cough suppressant like dextromethorphan can help soothe the irritation. If allergies are worsening your symptoms at night, an antihistamine like diphenhydramine can provide relief and assist with sleep. Staying hydrated and using steam inhalation can also ease throat discomfort. However, because you are experiencing chest tightness and weakness, it is very important to consult a doctor for a physical evaluation. This ensures your lungs are clear and rules out conditions like asthma or a respiratory infection. Please seek immediate medical attention if you experience shortness of breath.