Dream someone is trying to kill me?

Ive been having a lot of dreams like this but the last one really freaked me out because well when the guy who was trying to kill me (i know him in my waking life) i would stop him and even try to turn the needle...(it was a fluid of some sort he tried to inject into me to make me die a painfully slow death) anyways id try to turn the needle on him but i just couldnt but i ended up taking the needle from him and i injected it into his lover and his lover took it out and injected my mom and all i could do is sit there and watch my mom die and i felt so guilty the whole time :/ IT WAS SO REAL! i woke up crying! Can anyone tell me what this could possibly mean? Just dreams of ppl trying to kill you but never succeeding in general. you dont have to interpret my entire dream.