I took Seroquel for a while and it knocked me out after taking it. If I remember correctly I was taking 800 mg. I too have trouble sleeping and it really helped. I never got dizzy or passed out but it definitely put me to sleep.

I hope your pdoc calls you back soon. I know it is not a good idea to stop taking it all at once. They recommend ramping down unless it is a medical emergency.

Good luck and be persistent with your pdoc. That is what they are there for.