I've had this problem since...well, actually forever. For me it has a lot to do with stability, I have like none in my life. I'm always moving or theres usually always some kind of drama or tragedy happening. Sometimes it helps to meditate or read a book, and keeping a journal is very helpful, it provides an escape for my thoughts. If ur sleep patterns are off it could be ur thoughts are racing, so keeping a journal should help. Also keeping an orderly room, free of clutter makes it easier for some people to relax(helps me). Regular excersice is also important, sometimes it helps me to stretch before i go to bed. Another trick I use is to go into another room, perhaps the living room and try sleeping there, a change of venue sometimes puts me at ease. I hope one of these things helps you.