Sometimes deep tissue massage around the neck and shoulder helped to relieve some pain. The kind of massage that is bit uncomfortable like sports and Swedish massage. mine starts as a stress related headache and turns into a full blown migrane while I'm asleep. Headache wakes me up...

Another thing that helps is chiro.

It's different for each person. So massage may help or may not. I also sit under a really hot shower and just soak my head. Shower doesn't have to be full on just enough to get my head soaking. And I stretch my neck and shoulder as much as I can. Sometimes my back too.

Crossing my fingers for you and hope it breaks before you have to fly.