Is there something wrong with me?

im a 17 year old male and ihave been having these visions of myself doing terrible things to people i dont know. Its not always when i sleep i could be walking down the street and see someone and all of a sudden ill envision myself well to be frank killing them in very brutal ways and i feel it and it used to scare me but now its starting to feel good. these things have been happining since i was in 5th or 6th grade so about7 or 8 years and its been getting worse. its to the point to where ive started cutting myself to try and keep myself from hurting others