I am not a frequent migraine sufferer, but I do not think a month has gone by in the last fifty years when I have not had a migraine or very severe headache. But for the last three months I have been pain free!
The change? I started to follow a ketogenic (very low carbohydrate) diet, for other reasons, and noticed that my migraines disappeared. Other members of 'keto' groups I have joined report the same. One woman had had migraines since age three - and is now clear!
Now this is totally anecdotal. I haven't searched for any references or studies - there isn't much into low carb eating generally and the medical establishment is generally in the pockets of the big food manufacturers. Healthy eating of unprocessed foods isn't overly profitable for the food empires, so there seems little interest, or resources invested in the possibilites. It is entirely up to you each to consider whether it might help.
Ketogenic eating, with carbohydrates under 20grams per day, moderate protein and high fat intake is a big change, and was quite a shock to my system. That was even though I ended up there fairly gradually, first cutting out sugar and grains, then other very starchy vegetables, then seeing that keto might be the answer and really working on learning what foods contain carbohydrates. However it has transformed my health in a myriad ways and been entirely worth the effort.
If you are desperate, and I know a lot of people are, its worth trying, I would think. You will know in a month if it is making a difference!