I think you need to speak with your psych about this. If you were already on 50mg before, did this help your psychotic symptoms? You need to talk to them to weigh up how it's affecting you now with whether it's the right drug for you and if a change of dose may be helpful. It could be that something else will suit you more. I think you need to bear in mind that if you are tired all the time then your stress levels and anger are likely to be worse as well.

I have also been on seroquel (up to 300mg), only it didn't quite have the effect it seems to on everyone else, but I seem to have rather stubborn chronic insomnia.