I had really bad dizziness for about 3 months after my car accident. Everything made me feel nauseated, especially being in a car, sitting in front of the computer or going into a place with bright lights and lots of "commotion" (malls, grocery store, etc.) After about 4 months it went down more, and after 5 months it almost completely disappeared. I hit my head again at around month 5, and the dizziness and everything is back again. Hopefully, it won't take a full five months to go away this time, but I can honestly say from experience that it CAN go away completely with time.