I hope you find relief. Migraines are miserable to have.
I woke up around midnight with one and became violently ill afterwards. Tylynol and Excederin do not work on my migraines. I'll ask my doctor about the magnesium and see what he says. He's even prescribed muscle relaxers for me and they didn't work.
I can't try the food elimination to see if it's a food alergy since I don't get them everyday. I just went weeks without a migraine and all of a sudden, it's back.
It's good to toss ideas around to see what works, who knows, it just might work for you.