I was prescribed Metronidazole for associated antibiotic diarrhea...

I was prescribed Metronidazole for associated antibiotic diarrhea. For the first 5 days I had no side effect. On day 6 I started to feel fatigue and this symptom would seem to come in waves. It seems to increase this symptom as the days progressed. Now Im on Day 8 and feeling just completely out of it. Like i haven't slept or sort of a drunk feeling. I have to say that I have never experienced any side effects from prescription medication before so this is the first. I can't wait to get done with this. I just want to be back to my same self.