Why am I dreaming about killing my child?

I dreamt that I went to visit a friend who lived in Texas (in life I don't have any friends here). I did not want to stay but she said she would show me the house she had in mind. On the way there, we were dressed nicely and I felt like I did when I was a teenager going out on the town and had the attention and popularity that I craved and probably still desire (as my life has moved on and I live in a different country with little friends and family). On the way to the house we saw an old man who tried to kick me and my friend beat him off, On getting to the house, she introduced me to the same man and said that he had a personality problem and I needed to trust her that he was a good guy. The old man laughed and joked with us and went to get the keys for the house. Suddenly I had a dog with me and the dog began to whimper and I knew that something was wrong. I ran to my friends house and locked the doors and hid on the floor. I saw the old man peeking through the gl doors, pretending to call the dog. I saw my friend walking behind him and expected her to rescue me, but instead she allowed him in and told me that I must take whatever he does to me. It is only then that I can justify my revenge. No one will empathise with my actions of self defense, if they can't see the wounds that I am defending, I looked at the man as he was approaching and knew he was about to and bludgeon me and I saw a knife on the bed. I told her that I was sorry but that I could not do this. God would not want me to do this. I took the knife and began to chop into the man's wrists and watched green blood splash onto my face and clothes. I heard my daughter (3 years old) asking me what I was doing and I turned to answer her and she ran away. When I turned back to look at the old man, he had turned into my daughter and her arms were almost severed where I had chopped. I went to the bathroom to wash the blood off, and kept trying to tell myself that I did the right thing. I went to check on my daughter and there was a slight pulse. I called 999 and was told that it would be an hour before they could get here. I ran to get ready to take a black cab (?) to take her to the hospital and I heard her crying. I went to hold and she kept shouting at me to get away and that I was and I hurt her. I woke up feeling nauseous and confused. Please help.