At the end of April/beginning of may i had a sore throat that lasted 2 weeks, it wasnt strept since test came negative. it stopped for a week and now i have it again, i am extremely tired all the time, i have white patches in back of my throat, test said it isnt strept, ive been taking cephalexin 500mgs. i am 21, a vegan and recent ex-smoker. what could it possibly be? i am a singer as well and need to get better, but dont know what it is to treat it. my physician isnt much help, he s old, tired and incompetent.