Hi! I am sorry to hear you are suffering so much. And for so long! I have been dealing with chronic migraines for several years, they sort of came on out of nowhere. I see a neurologist and another doc that specializes in migraines at a headache clinic. They figured out a plan which has greatly improved my quality of life. After trying lots of different meds, I found the clinic, and have gone from having migraines every day to having only a few a month, and even those are much less severe and shorter in duration.
My treatment consists of: avoiding things like caffeine and narcotic pain meds (they trigger migraines for me), getting botox injections every 3 months (lifesaver!!!!), taking preventative meds (verapamil, baclofen, and namenda) a few times daily, and of course, I have rescue meds (naratriptan, zofran) as needed. The botox sounded kinda scary at first, but I have been doing it every 3 months for the past 1 1/2 years or so, and I cannot tell you how much of a difference it has made. It's 31 tiny little bee-sting feeling shots in the forehead, temple area, scalp, and a couple in the back of the neck, down to the shoulders. Takes only a couple of minutes, kicks in within a couple days, and the only side effect I have had is that I cannot raise my eyebrows...but who cares?!
I don't know if those treatments would need to be different because of the barometric pressure factor, but I wouldn't think so. I don't know.
I know the verapamil I take is some sort of blood pressure med, I've been meaning to look it up and find out how it works. I have some issues with lightheadedness and my bp has been rather low lately. I'm thinking maybe I just need to lower the dose a bit (under doctor's care of course!).
Feel funny writing this today because I have a bit of a migraine today, worst one I've had since January, but it's still not bad enough to interfere much with functioning--just kind of taking it easy today.
I really hope you are able to find treatment that works well for you. I am assuming that you see/have seen a neurologist who specializes in migraines.
Let me know if I can help in any way. I have no doubt that you can and will find something to ease your pain!