Hi Paniccu, It's so interesting to hear so many people with similar problems to me! And I thought I was a weirdo! lol. Yes, my first attack of tachycardia (which led to a panic attack) when I went to the ER I think was brought on by Excedrin. That used to be the only thing that worked when I got migraines. Now I usually just take a couple of ibuprofen and lay down in a dark, quiet room. It seems like putting a cool pillow partly over my head, like on my forehead helps, and also massaging and putting pressure on different points on my head/forehead/face helps. Also, keep laying quietly until a while after you think it's over, if I get up too soon, it quickly comes back. The heating pad is a good idea, sometimes I use one of those gel face masks that you can chill or heat, but it seems like those don't hold heat very long. They do go right over your sinus area which helps if it is sinus-related. Oh, almost forgot - I have used a product called MigraSpray (sp?) that I think is herbal, it is a liquid that you spray under your tongue. It seems like it helped to some extent, but it's been a while since I've used it. I'm not at home so I can't see what's in it. Good luck, hope your migraines improve!
And don't panic, migraines and headaches are very common, a brain tumor would be a very rare thing. It's like one time I had an eye infection and went to the eye doctor, worried that it was this virus that can cause blindness, and he said something like, "when you hear hoofs galloping, it could be a herd of zebras, but it's a lot more likely that it's horses", just to illustrate that just because something is possible, doesn't mean it's likely!