HELP ME PLEASE!! i need somebody to help me, im losing control of my mind, my sense of reality and my life?

i asked a previous question about whats happening to me and the responses i got was psychosis, now what exactly is a psychosis? my dreams have been affecting me everyday...making me depressed or just thinking about when im gonna die or when is this guy gonna come finish me off, ive attacked my family members in fits of rage in ager and in just that i want them to understand the pain im feeling, i feel like my world is a walking timebomb, and im set to die at any moment. sometimes i will be walking down the street to take my mind off things and suddenly i cant hear and all i hear is my thoughts and heartbeat and then its like my whole world flashes to black and white and everything is slowing down. and i turn behind me to see my attacker walking up the street with a knife that is dripping with red blood and try to run away but im not fast enough and he just grabs me and forces me down and just hacks away at me.. and then just as soon as the attack started it ends in a flash and im back to reality..this used to happen in my dreams but its not transferring into my everyday life..so much that people are becoming afraid of me and are calling me a psychotic, sometimes its my friends, which hurts the mos because i thought they were supposed to be there for you, URGENT PLEASE HELP!!