I cant stop thinking of murder (serious post)

I dont wanna come off as edgy or trying to get attention, i genuinely want advice and help. I'm 19 and male and for the past couple months (roughly 2) i frequently think of killing other people. Not usually innocent people but I'd be lying if i said i haven't plenty of times. For example whenever someones even slightly agitating me i cant stop myself from thinking of ways i could end them, i dont exactly want to think like that but i hate to say i dont mind it either... Its very prominent when dealing with people i know have done terrible things (SA, Murder, etc). I dont know why i feel this way and think the way i do, is it a warning for future mental problems? If you have anything that can help please tell me, i dont want to become a guy on the news but i feel i have a subconscious desire to do harm.