What Causes Bad Taste In Mouth Along With Dizziness?

I get a bad taste in my mouth. Food and water doesn t taste right. Then I notice that I am feeling dizzy. After that, I fall asleep for up to 18 hours. If I don t go right to sleep, I will continue to do things and have conversations that I have no recollection of. This can happen once a week, or go as long as 6 weeks between episodes. It has been going on for nearly 10 years now. No doctors can find anything wrong with me. I am fine between episodes, and suffer no pain.