What Is The Right Dosage Of Diazepam And Nitrazepam Need To Be Taken For Psychosis?

How much diazepam and nitrazepam would I have to take for it to be an overdose and what effects would it have on me. I had 10mg nitrazepam and 8mg of diazepam. I suffer with episodes and psychosis.. I m a little concerned as I took it to help me sleep. Its not prescribed to me! Help please