I am on my 3rd antibiotic and now predinsone to rid me of this scurge of an infection I got. Same symptoms as you, sinus, sore throat, antibiotic, goes away, come back, sinus, chest, sore throat, antibiotics, goes away, come back, ear ache sinus infection, antibiotic, steroids this time and Levenquin. Its going away but putting up a fight. The doc said there was a bacteria going around that seems to have built up some resistance to commonly prescribed antibiotics, he had it as well and it took him 3 rounds of antibiotics to rid himself of it.