I had trouble with this as well for months rreihart, I was waking up with headaches and dizziness in the middle of the night, wasn't able to fall asleep after getting up. I found that it was partially due to lower blood sugar from fasting all night during sleep. I'm almost convinced that one of the symptoms of concussion is extreme sensitivity to lower blood sugar since I never had anything like this before getting my concussion.

What's worked for me is eating yogurt or a small piece of chocolate when I wake up feeling like this in the morning or in the middle of the night. Might be something that might help tone down the severity of your symptoms