It seems i can no longer take medicine with out getting anxiety. it could be ibuprofen which i have taken many times or the zpack. why?

Sometimes.: Some medications , even antibiotics , can cause side-effects ,including anxiety. You need to remember what these medications are so you can avoid them in the future and look for a substitute. Eventually you can come across a medications that does not cause anxiety through a process of elimination. On the other hand, you may anticipate anxiety and that can be a self-fulfilling prophecy.