Sounds like the seroquel all right. I would talk to your psychiatrist. They may slower the dosage for you.
I was like that with my trazadone. I was so tired for a while and then I got use to the medication and now I am fine. I agree give it a little while longer and see if you get use to the medication.
Seroquel will do that to you. How long have you been taking it? If it's not long, give it a couple more weeks and then talk to your psychiatrist about a med adjustment if it hasn't stopped.