I have the same exact sleep problem as well.
It's hard to fall asleep and then I wake up at night totally alert. Takes me over an hour to fall back asleep and then I feel very groggy in the morning. And most of my sleep is not very deep.
I think most of it is related to anxiety/depression.
I used to take melatonin and the smaller dose actually works better for me for some reason (1.5 mg vs 3 mg).
Here's an article about "Adrenal fatigue" that I thought closely describes my sleep issues -
http://www.adrenalfatigue.org/sleep-disruption