Wow, that sounds really scary, Cats your dreams could have different meanings, especially depending on your thoughts and your feelings as of lately... have you been going through any difficulties and/or depression? or are you dealing with something that you feel like you're not necessarily ready to face? The idea that you're being chased and fighting for your life could be symbolic for either suppressed feelings, or any kind of emotion/situation that you're dealing with now. It probably feels so real when your asleep because it is real, just maybe not in the literal physical aspect that you perceive in your dreams... It's a bit hard trying to decipher your dreams, without delving into your thoughts and your feelings, but I hope that this has helped if you feel comfortable enough to elaborate, maybe I could help you more - if not, then I hope that these nightmares stop soon, and that things get better