so, instead of applying heat or steam to your head, apply an icepack (with a cloth around it of course) to where it hurts (
for the majority of people, heat on the head irritates the heck out of a migraine, whereas
cold relives pain). Use the migraine meds instead of the sinus meds when you feel any "sinus" pain as it could be the first signs of a migraine attack.
Of course, it's just a suggestion...