Showers help against migraines?
They help me. I discovered a special technique years ago that I've been using ever since (migraine and severe headache sufferers take note)..
When you get in the shower, let the water get warm, then plug up the drain like you're going to take a bath. While the tub fills up, wash your hair like you normally would, then take your wash cloth (if you use one), get it wet if it's not already, and lie down in the tub, letting the shower water hit your stomach/chest area.
Let the tub fill up until the water is to your shoulders (or wherever you feel most comfortable stopping it). Grab your favorite soap (I have a eucalyptus one that I use only with migraines), drizzle some on the wash cloth, fold it in half, then half again, put it over your eyes (or on your forehead) and lie there for a few minutes doing some deep, calming breaths.
This can help with most headaches. :)