They say that people are out to get me...

I dont feel right. Ever since my dog Lupo died last year. i hear voices during the night and day telling me i broke the promise to him and i should punish myself and cut my wrists and legs, the voices tell me that the people on my posters are watching me so i have to put blue tack on their eyes so they cant see me.
They say that people are out to get me, and the nurses that give me injections are also after me to peirce me with thier needle and poisen or try to kill me,i was with my mate one day and i thought i saw something that wasnt there so i got scared. And today while writing a report for a school project i saw a picto gram of someone giving blood. i backed away from the laptop quickly and started to cry and said to the voices to shut up but they just kept singing laughing talking about me. i cant be around big groups because i get paranoid around them, my best mates tried to help with that but it didnt work and i felt like i was going to faint. i cant eat in front of people, im self concious on how i look. i lose concentration easily and get angry easily, im currently hearing footsteps right now and i just checked nothings there, i constently feel people are following my every move and deciding for me and i allways get my speech muddled up. whats wrong with me?