"I find that the low THC, high CBD combo is keeping me awake, not helping with insomnia. I read a few articles on Pub MD and see that CBD increases wakefulness. What is the recommened amount of each to help with insomnia?"
It really differs per person, generally a high THC in an Indica strain will help with Insomnia. Stay away from Sativas or Hybrids with Sativa dominant.
To answer your question: It depends on the tolerance level of the individual.
I find my body reacts in a similar way to what you've described. I only take the low THC high CBD combo tincture in the morning now.
For sleep aid, I focus on heavy indicas in flower, vape pen, or dab-able concentrate form. Low dose edibles like Kiva's Blueberries taken a half hour to hour before bed also work well, but can give me a little residual sleepy hangover (like nyquil) if I consume more than one.
Dosage is about the most personal thing out there-- and sure evidence that everyone's body is different so there is no one-size-fits-all medicine. Any dosage recommendations should read: take a small dose (and record what you took) and wait an hour. Repeat until you get the effect that you need (of the THC). CBN is a cannabinoid that seems to be most responsible for sleep-- though it is sometimes hard to find things containing a higher CBD amount. If you are in CA try our Snooze Bar as it is formulated with superfoods (poppyseeds and nutmeg) and Ayurvedic herbs to help with sleep.