I am 41 y/o and have these, what I call night terrors, for at least 20 yrs where someone chases me then corners me in small dark places and is violently trying to kill me. In my night terror I try to scream but I am paralyzed and my scream won't come out of my mouth. My children and others who are in a different bedroom and sound asleep can hear me trying to scream which is a loud moaning sound (described by them) and come wake me up. I am completely paralyzed with fear and always am awakened seconds before being killed and seeing the face of the person trying to kill me. They are extremely vivid and my throat actually hurts from trying to scream.

Try to change your dream think about something elce

Hi, I'm sorry that your question wasn't noticed until last night. The first response has a lot to it: people can will themselves to change their dreams, with time.
Having night terrors so often and for so many years is a bit unusual, and I wonder if it has an emotional component (mugging, rape, near death accident, seeing someone die in front of you?) or a physiological one.
Can you think of any incident when you are about 20?
As for help, there are various techniques at home. For at least an hour before you go to bed, don't watch TV or your computer. Do some soothing reading, whether a book you know, some seed catalogs, or listen to soft music. Don't have anything to eat at least 3 hours before. You could drink some warm cocoa made with real milk and very little chocolate. Find a song or poem you like and repeat it over and over as you fall asleep. I like the Song of the Wandering Aengus by Yeats, and several old soft songs. Have a night light, or even a short string of little Christmas lights.
You could have some chemistry that sets off your brain in the middle of the night, and such things aren't well understood. You could try a sleep study at a university, if there are any near you.
There is some evidence from studies with soldiers that flashbacks can be helped with blood pressure medicine if taken just before an attack. There might be something similar to flashbacks going on in your sleeping brain. A sleep study would monitor your BP. You could get a BP cuff and measure your own when you wake up in the night.

I read a great article on this subject at

Recurring Nightmares - How Do I Get Rid of Recurring Nightmares? (http://jerryg2.hubpages.com/hub/How-do-you-get-rid-of-recurring-nightmares)