What Causes Dizziness With Pins And Needles In Arms While On Zinnat?

I took Zinnat 500mg twice a day for 7 days to treat an infection that showed up in blood tests. The treatment has left me with cotton-wool fuzziness in my head and tingling/pins and needles plus heaviness in both shoulders and arms. My head, shoulders and neck are very uncomfortable, and it is difficult for me to get to sleep. It is hard to raise my arms above my head, an my legs, too, feel very tired as if I have been doing a work-out. I am 22.