I ended up going to bed last night just past 7pm. About 4pm yesterday, I was suddenly struck by a massive headache that quickly built in intensity. I'm not sure what caused it, but I suspect that I'd eaten something with lots of MSG in it and didn't realize it. This wasn't one of my cluster headaches but a full blown migraine. The cluster headaches are more of a nuisance nowadays than a major pain. The medicine I am on for them keeps the intensity of them mostly to a low roar, but I still have migraines occasionally and last night was one of those. Even though my migraines are quite rare these days, I do still have some of my old migraine medicine. I took that medicine, but the problem with my migraines is that they always cause a tension headache as well and those can be as bad as the migraine and more difficult to get rid of. Usually sleep is all that helps. In this case sleep did help. Now I pray that I will be headache free for the next two days, which will be very busy days at work.