Had a very sore throat (still have tonsils), hard to swallow, felt very weak, hot and cold, and a fever of 102. Went to the doctor, test for strep came up negative, however was prescribed a Z-Pack for 5 days. Most symptoms cleared up the next day, sore throat cleared up on last day of meds. However sore throat is already back one day later, and about as bad as before. Very sore, hurts to swallow, and feels like there is a lump in my throat. Any ideas?