What Causes Nausea And Dizziness In Supine Position Post Injury?

i m 37 year old female with PKD, and recovering from a car accident, broken nose, herniated disk in L5/S1 and whiplash. I m on oral prednizone, 60 mg daily of Cymbalta daily, Amnitryptaline 20mg a day (for concussion). I rolled over in bed and my room began violently spinning. If I closed my eyes it got worse. During this episode I could feel my eyes darting back and forth. It lasted for 5 minutes. I couldn t even sit up. I could feel gravity pulling me down. It was nauseating and terrible.