My nightmares are about killing my family

This is driving me crazy. In general I am a very composed, relaxed person, who overcomes things quiet easily. I don't even harbour any loath towards my family and my most beloved person in the world is my little brother. Since I was little, I would see dreams where I couldn't save my brother but would try over and over again, until the nightmare couldn't stop looping until I save him. I see nightmares quiet often, but I don't regard them as nightmares since I always turn the tables in the end and they have a neutral to good outcome. However, the past months I feel tortured. I can't even describe the terror etc etc. It all begun with a nightmare, where there were kids, tied from their ankles with chains and there was a man in front of them. The first time I saw an unknown person which seemed 100% legit (you know how when you wake up all the strangers and stuff seem not legit and you laugh). But it was like he was real indeed. I couldn't move or do anything. Then it was a deaf lil' girl who was also immune to pain. I didn't know her either. The man took a bat and started hitting her head. The other kids were watching in horror. I couldn't move, nor scream. The girl knew that something was wrong and started crying but she couldn't feel pain. Hair brains started coming out from her skull's cracks. I couldn't do anything. Then I saw that my father lost it, and with a shotgun he was trying to kill me and some other people. In the end, I have managed to take him down, and stabbed him with something sharp on his lungs. I have found a weapon and tried to shoot his head, but it wasn't loaded. So as he was dying, he regained his senses. And there I was crying over his half-dead body. Of course as in the first and next dream, I woke up crying uncontrollably, I was suffocating, and had my heart race faster than ever. And then, I saw that I was being chased to be stabbed to death again. My little brother was chasing me as well, but it was my little brother from 6-7 years ago. I stabbed him with 3 knives at the chest again, on the left side of his torso as with my father. He as well came back to his senses while he was dying. I was trying to comfort him, touching his shoulders, and the sensation of his skin was so real, as when it is during summer time. Then I woke up again. These nightmares, repeat themselves in different ways, and I wake up devastated. What is the rational explanation to this? Is it even normal? Before I hear any suggestion that I have hated them in the past and such, not that's not even the case, especially for my little brother. Nor past bad experience with him. And no I am not such an emotional person. I have overcome my rape years which started when I was 6 and ended when I was 12-13 and I have managed to let it go all by myself, after falling into depression for many years I overcame it, and little to no thing causes me trouble, except if I am not productive in my everyday life. Is there any rational explanation anyone can give me out there? Thank you.