I was prescribed Doxy one week ago to treat a sinus infection, and have been taking it twice a day (100 mg x 2 = 200 mg a day) and one week later i am MISERABLE. The migraines I've been feeling are indescribable. The body aches and pains and the fatigue is miserable. Ive never had a headache so bad as this. Also I eat a little bit then feel so full and disgusting it's unbearable. I will NEVER take this drug again.