I was prescribed DOXYCYCLINE HYCLATE 100 mg for an acute sinus infection. I have been taking it for 3 days now. I am having the following side effects. Should I continue taking this medication? SIDE EFFECTS: Severe Headache, dizziness, blurred vision, body ache, loss of appetite, itching and anxiety. I only get about 1 hours sleep before I wake up feeling very strange and a feeling like I cannot catch my breath. My Doctor will not be in office until Monday.