My grand daughter is 16 years old and she has not gotten better in 2 weeks with 2000 mg Amoxicillin then was changed to Zithromax. She has been tested for Mono twice and both were negative. Her symptoms are: headache, light sensitivity, fatigue, back pain, very sore throat, neck stiffness, hot and cold flashes, body aches, loss of appetite, cough, stuffed nose and nausea. She is overweight and has been bitten several times over the last few months by mosquitos. Do you have any idea what it may be?