Trouble focusing on anything – natural remedies?

I was once diagnosed with ADD, then with Asperger’s, and at one point I decided that both of these diagnoses were the popular diagnoses at the time, according to what I’ve heard and read, so, for the most part I now choose to ignore them both, despite evidence that I may in fact have AS. There’ll always be something doctors can pin on anyone and say they need to buy meds for it.

But in my case, I’m a poor college student whose budget goes to books and food, and in my own case, I’d rather toss 0 for a year’s membership at a gym than the same dough for a couple months’ supply of whatever pills doc Smith has to push.

Either way, I have trouble focusing on anything – I can’t sit down and read a book for more than 20 minutes to save my life. If a movie’s over 2 hours long, I’ve taken 3 bathroom breaks and am sipping on my fourth 42-ounce refill while I twiddle my thumbs. Studying for anything, for me, is torture – long lectures, my bane.

Are there any ‘natural’ solutions for me?
Experience:
Doctors push pills. Most of my family is in medicine. A relative of mine, for example, denounced one of the products I had been put on (Provigil), though he himself sold it in several places.

I’m not looking for quack alternative medicines, I don’t need someone to tell me to detox my colon, burn incense, smoke grass, pray, and flog myself, but I’ll take some advice as far as altering my diet goes, or particular forms of exercise, as long as it doesn’t involve sprinkling magic powder in my orange juice.
I might try the ginkgo bilboa. But I simply can’t afford to visit psychiatrists, or try a handful of drugs at apiece each month.