One thing that improved my focus was taking saffron capsules, the kind you can find at most drugstores and health food stores. Started with 30mg once a day and upped it to 60mg. Some studies have shown it's as effective for treating ADHD as Ritalin is.

It can get expensive though. Might be a good way to check if you actually might have ADHD so you can get tested (if you have robust healthcare that will cover the cost of doctors/prescription drugs.)