I have this same issue with lamotrigine.

I talked to my physician about my options regarding the timing of my medication. I take my morning dose when I get up at 6:30 am. Then I take my night dose as soon as I get home from work at 5:30 pm.

Once I started moving my night dosage closer to supper and away from bed time, I found it much easier to sleep at night.

I take the same medication I have found it hard to I'd b still awake until 5am my doctor told me to drink herbal tea and that doesn't work I just drink hot chocolate and my sleeping time has improved to around 2am now I'm trying to cut down to hot milk and hopefully down to 11pm

Many times i find myself to be tired during the day, then cant sleep at night. I have found the tinctures Skullcap, and California poppy seem to help.

I dont allow myself to have caffiene coffee after 3pm and listen to scripture tapes as I fall asleep and have not had trouble since.

My dose has been lowered and I'm still having drowsiness, nausea and dizziness