What Does Metallic Taste In Mouth Mean?

I have been nausea, extreme fatigue with a mild fever for last 3 weeks, I have seen my Dr and he thought it was a stomach bug and gave me metronidazole 500 mg 4 times a day for 7 days and if not better to call, called him 4 days after with no improvement was still not able to eat solid food even bread without feeling sick, so he called in ondansetron 4 mg every 6 hrs. Was able to eat food finally last Friday but was still nausea even with meds. I contacted my Dr on Monday bc I was having symptoms of burning when I urinate even though I was on meds still. Went yesterday and the password told me I have a lot of white blood cells and blood in my urine. She gave me another antibiotic nitrofur-macro 100 mg 2 a day. Last night I woke up at 3am with a pain in my left shoulder blade and a metallic taste in my mouth. No one can tell me what it could be, any recommendations? Thank you