Well; this is a thread with PTSD at it's center. Many high schools have psychologists on staff, and that is the place to go for this sort of thing. If your dreams are affecting your grades, or you fear sleep, it is time to seek help, like you did. Problems with sleep can start when you are using the bed for something other than sleep, and one other thing. If you are reading a Kindle in bed, you will have sleep problems. The same is true if you are using a tablet or IPad in bed, it will impact your ability to sleep. Latest research is going so far as to say keep Cell phones, Tablets, Ipads, and anything with an LED light lights. They do disturb your ability of fall to sleep, and stay there.