One option that has a good success rate is a magnesium supplement. If you do some online research, you will find a lot of advice.
I think it relaxes the blood vessels, but haven't read up on it lately.
I take it for muscles spasms and soreness, and it works wonders.
I was getting chronic headaches, not migraines, and it was from tight muscles pulling on the head.
As with a lot of things, there may be multiple causes and treatments. Never easy, though magnesium may be.
See my mosaics