After 3 days of doxy I had chest and back pain...2 days later ext...

After 3 days of doxy I had chest and back pain...2 days later extreme headaches on right side of head. My husband told me he thought it was the doxy, but at first I thought it had to do with the medical procedure I had. I went to the emergency room(i thought i was having a clot or something) and they just said it was a combination of everything I had been thru. I now don't believe that. I have had a lot of problems with headaches before, but when I get a severe headache is usually when I wake up tired. I have woken up completely rested and still severe headache. Doctor thought it also could be rebound from benadryl which i don't believe. I also have had some itching here and there(thought i was allergic to a new soap). I have been off the med for a week and still having a problem with this weird headache. When is it going to stop????