bacterial infection
"Im on a 7 day course x2 a day on Metronidazole. I felt fine the first 2 days no side effects really.

But yesterdays (day 3) i could hardly eat i was sick and dizzy, vision is a bit blurry and hard to focus. Also thinking is slower and speach has slowed. 

Day 4 which i am on now, my head is fuzzy , im hungry but the thought of food is making me feel worse i can just about drink water, and have been exhuasted still feel slow and sluggish, speach is still slow and even struggling to write this! I have noticed its working but these do mess you about!"