I'm almost convinced that many of our pain issues are allergic reactions to food. Headaches are caused by the swelling of blood vessels in the brain causing pressure which in turn creats the pain you feel.
I too suffered from severe migraines and noticed when I would eliminate wheat products from my diet the headaches would go away. Two days ago I made the mistake and ate a hamburger..I am still suffering from that. Do a search on "gluten intollerance" and let me know what you think.
Give the Amitriptyline a chance to work... I was orginally started off on Nortriptyline... though I was almost started on the Ami... and I was told it take 4-6 weeks before you know if the medicine is going to work. Also with most (if not all) drugs in this class you need to build up to a theraputic dose slowly... I would be suprised if they started you off at more than 50mg.
The fact that you are showing some good response to the medicine already only 7 days into this is very promising!! Give the meds a chance to work.
I've been able to do self-hypnosis which helped a lot with my headaches... only it wasn't the best solution because I still wouldn't be able to do anything much... only I was in as much pain then.
Good luck and lets us know if your response to the Ami improves!
Also... if your dose is less than 100mg and your doctor didn't give you instructions to increase it call and ask if you can especially since it is helping a bit now... I'm not 100% sure on this but I think the theraputic doses of Ami can get up to 200mg... but don't quote me on that, it's been 4 years since I researched this class of drugs and I'm working off of memory here. :)