Welcome to PC and hope that you feel at home soon.
I have been on Seroquel for sleeping and anxiety for a number of years. I wanted to decrease the amount down from 100mg per night. I halved it and found that sleep wasn't as easy to come by. When I forgot to take Seroquel I would lay in bed awake.
It is dissappointing that he said that it was 50mg or nothing.

Sounds like that the p'nurse knows more than the P'doc. Might not be a bad idea to get a second opinion from another psychiatrist though. CANDC had some very wise words and great advice.
Getting quality sleep is going to impact our mental wellness.