Its amazing reading your post because its like the story of my life.
I first had a panic attack at a busstop outside a hospital. I was that scared i called 999 becuasei thought id die if i walked any further. Embarassing.
I also have dropped out of college and worry about everything i could possibly think of. At the moment its 2012, im worrying my pants off about it. And for the headaches, i also think i have some sort of brain tumor.
Hope you find something to help you through this!