(Tarantism)
Psychosis can be present with many illnesses. I have complex ptsd and family members with schizophrenia. I do know that the sooner psychosis is managed medically, the sooner recovery can begin and the greater the chance for a full recovery. So, having said that, I know it is difficult for you to trust right now but I do think it would be in your best interest to find a facility or pdoc you can work with. Try to get a recommendation from someone you trust - is there a family member who can help you?
As far as the screaming voice is concerned you might want to try using headphones with a meditation or some gentle music to sort of drown out the other voice or give her something to listen to. Maybe it's a scared part of you. I have found that when I have a lot of head noise, listening to tapes really helps. Also, prepare yourself for sleep by taking a bath and drinking some warm milk or sleepytime tea.
I hope you can get some rest and some help.
Take gentle care.