Thank you, jon019.
By the way, I looked at my left eyelid, where the CH always happens. It seems swollen. When the pain was happening, I think that I might have been tightening my orbicularis oculi (the facial muscle around the eye--I looked up this name from a diagram just now.) I hope that's the cause, not some new symptom.
I should post my story in the right place, but I'm 44/m, and had three overall cycles. The very first in 2012, and I had no idea what it was--lasted a week. Then 2016, it started again. At first, doctors didn't know what it was, but one finally did. At first I was prescribed sumatriptan and ondanestron, and soon after that verapamil. The CH's kept going, even 2 weeks into the verapamil. Around that time I discovered this website, and read some posts by Batch about high dose Vitamin D. I went ahead and took some, and I noticed a few days later that the CH were less intense each time. Wonderful when it finally stopped. I took around 5K IUs per day after that until last year, I was monitoring my blood levels, and they kept creeping higher, 67ng/ml up from 53 soon after I started taking that dose. I reduced the dose to 2K/day. (Probably a big mistake). I thought it was sufficient, but in retrospect it probably wasn't. The nemesis from the past started last week after 2+ year break. Needless to say, after it was clearly happening, I started popping more vitamins. The past three days, I took at least 10K/day. I hope the VitD was the reason it ceased last time, so it should work again. I'm kind of skinny, so maybe I can't store much.
Sumatriptan: is the generic 50mg pill. When the pain starts, I look at the clock, and hope it starts working, but it seems to take forever, and sometimes doesn't help at all. It's best to take with empty or partially filled stomach, I think. I am concerned about side effects, so I really don't want to take this.
Threw up a couple times last week, and took ondanestron, and seemed to prevent it. As you might know, it causes bad constipation, so I decided to forgo that one, and roll the dice with the chance of vomiting.
I didn't try any other type of preventatives. I read someone's post about trying a hot water foot soak, and another thing about cannabis. If I feel the onset of an attack tonight, I will try to soak my feet in very hot water.