Screaming or howling

I wake up at 2:45 half in and half out of a dream...there is a strange are loud siren ringing in my ears, almost like an electrnic alarm but of massive scale...i realize i am in bed sleeping and must be dreaming. I try to wake myself up. as I become aware...eyes still shut...I cannot tell if the sound is real or not...until they start to fade. I have trouble figuring out where I am. I have to focus...my heart is racing and I cannot remember where I live or anything about myself for a few moments. It starts to come back as I start to recognize shapes in the dark.the window, my guitar case. I am in a room...what room? Is it my room? Where am I. Where do I live? In nc. I live in nc...in a house? No. An apartment...I left my house, my wife, months ago. My memory starts to return.I start to relax...but as I do, the wailing sirens return, excrusiatingly loud. It is interesting, I think to myself. I wonder how loud it will go. As I try to return to sleep, the sirens always get loud enough to wake me to the silence. I concentrate and manage to relax and control the sound in my head..as I start to fall back to sleep...then...movement wakes me...at my back. Something rubs me...feels warm...something alive and big enough to be a cat, maybe a dog. I lay still...do not want to startle it. I reach my arm back slowly, expecting to feel fur...I feel skin...an arm. ITS A PERSON. I think to myself in my still confused half awake state...is it <PERSON>? Then I feel an arm around my neck hard...I lunge to get away but the arm is strong and I am soon wrestling for my life. I manage to get my feet on the ground and turn toward the intruder. I see his face in the darkess, grimacing...he is a young man, taller than me...I am in a fight for my life. Then I feel another body grab me from behind. I am being choked. I cannot breath...but I am choking the man in front of me too. I think to myself...if I kill this guy, I might survive. But as I choke him, I start to pass out. I can sense the end is coming. I fought a good fight, I am going to die well.then... I hear a funny ringing sound, not a siren, this is different...I recognize it...it is my cell phone. I realize i am sleeping and someone is calling me but I cannot answer it though because somehow I rolled in my sleep in such a way that my right arm was wrapped around my neck and my left arm was under my body.both were asleep and i was partially cutting off my own air supply. I did finally answer it...it was <PERSON> from a company who I work for in NJ.there was a critical software failure at month's end and they needed my help. It was 3:00 sharp. The details of the dream are still fresh. I even remember the intruder's face...he had pale skin, blue eyes and short red curly hair. He was big and strong. The one behind me choking me, I could tell was smaller and had big forearms...like mine I guess. I remember that the imagery of the room was extremely accurate, the position of the bed, the guitar case, the dresser...the size of the room...even the ambient light coming from the window that lit up the man's face. Would love to hear comments about this, especially the siren. It was the only thing about this episode that concerns me, never had anything like it before. The way it filled my mind and went through me in chilling pulse waves...waves that I could almost control. And the overwhelming terrrified feeling and chills that I felt that came in waves in sync with the sound.