Suggest Treatment For Sore Throat Causing Difficulty In Breathing

I've had a sore throat, scratchy for ages and blocked up nose with headache which subsided around a week ago. So I went to my doctor (yesterdfay to be on the safe side) and they said it was sinisitus and gave me anti biotics. However Ive been feeling far worse. Im finding it hard to breath out of my nose and throat as both are so iratated.