Hello, As long as you are not having a fever, it wouldn t sound like you have a bacterial infection that requires antibiotics. This may be from a viral infection that has since passed, but afterwards, the airways can still be irritated and inflamed. If you have already tried an antihistamine/decongestant combination like Claritin-D, I would suggest adding a nasal steroid spray like Flonase, especially at night when you have the nasal congestion. This can help reduce the inflammation and clear out the nasal passages, which hopefully can help with a sore throat and cough as well. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Aaron Branch, General & Family Physician