Disturbance in sleep may be due to anxiety, depression and high stress level.
In addition to over the counter medication there are natural supplements that can improve sleep. Amongst those are: magnesium, GABA, melatonin. L-Tryptophan and 5-HTP.
Try to reduce your stress level, do not consume alcohol or heavy meals before bedtime, no TV, etc. Relaxing baths and soothing music can also help. If you are unable to sleep, it is best to remain in bed versus getting up to use the computer, read, etc.