What does this dream mean?

i had a crazy dream last night that there were infected animals who had some sort of rabies, they were horses, cows and dogs. they were biting people and turning them into zombies. they surrounded the house i grew up in but do not live anymore, nobody believed me that these animals were dangerous. my dad was there and wanted to smoke a cigarette outside, he actually does this in real life, i told him not to because i was scared that he would get sick by the animals. he said not to worry and smoked inside our old house. then suddenly we were in a building that i use to work in on the same floor, floor 23, but it was empty, and we went to a room in the middle of the building were people were hazing other workers mainly male. i told them that we need to lock up because there were crazy people on the ground level who would tear us apart like zombies. thats when, and i'm not joking, Justin Bieber came in and tried to calm me down. he took me to the window to show me that there were no crazy people down there but to his surprise there were. we quickly went to the middle room that had gl walls and locked it up with wire that looked like guitars. as we saw a rush of people come into the other room some scared some not knowing anything was wrong i saw my sister and my uncle come in all very calm, i tried to open the door and scream for her but she could not hear me and the other people told me to stop or else we would all die. my sister kept smiling and laughing with my uncle not knowing anything was wrong when the infected came in and i lost sight of her because my dad and Justin Bieber grabbed me and told me to forget about her. at first we were safe in the gl room but then the infected started to break the gl, so we decided to make a break for it, me and five other people including me dad and Justin Bieber. we made it to a bus where my sister was but somebody who was infected was on their and tried to kill us all. what is up with this strange dream?