Olanzipine usually helps make me feel tired - tbh im surpised the diazepam doesn't help make you feel sleepy - i know it certainly has this effect on me! You've probably tried these already but i would take a hot bath, drink something warm and read something light before going to bed. During the night i take the covers off me for a bit then wait till im so cold i can't stand it then when i put them back and begin to feel all the warmth and coziness again this helps me drift off - what does your doctor think of all this?