Not a cure, but what I found that helped me when I went through a phase like that was crashing on the couch in front of the tv. I would turn it to a boring station, turn the volume down real low and then get comfy under a warm blanket. The sound of quiet talking kept my brain from getting active with my own thoughts and I usually managed to doze off. Sometimes I would wake up periodically, but then I would doze off again. It's not the best solution, but it is better than nothing.