I have to agree about DiNotte. Caution, Noah---lighting is addictive and you develop a tolerance to it. I had a first generation DiNotte Ultralight for a few years. 140 lumens and I thought it was awesome. Then I upgraded to a 200L---and I couldn't believe I rode with the Ultralight for so long. I followed that with a DiNotte 600L---wow. Now when I ride with just the 200L I find myself longing for the light of the 600L. :-)

And----holy crap! You rode 200K on a bike with flat bars? No wonder your left hand was still numb. Drop bars, man. Nitto Noodles, especially, are your friend. They're perfect for your situation. I can't imagine riding any sort of distance with only one available hand position. That's a good way to develop a chronic injury.